What are the technical parameters of diamond drill bits?

Technical Parameters of Diamond Drill Bits: A Comprehensive Guide with Brand and Model Details

Diamond drill bits are critical tools in industries ranging from geological exploration and mining to construction, automotive manufacturing, and precision electronics. Their performance is directly determined by a set of technical parameters that define their size, material composition, structural design, and operational capabilities. Unlike traditional drill bits (e.g., high-speed steel or carbide), diamond drill bits leverage the extreme hardness of diamond (the hardest known natural material, with a Mohs hardness of 10) to cut through rigid, abrasive materials such as concrete, granite, marble, reinforced steel, and even synthetic composites. To fully understand their functionality and select the right tool for specific applications, it is essential to break down their technical parameters into clear categories, explore how these parameters interact, and examine real-world examples from leading brands. This guide covers every key technical parameter, explains their significance, and provides detailed specifications for popular models from top manufacturers, ensuring both technical depth and practical relevance.

1. Basic Technical Parameters: Foundational Specifications for Sizing and Compatibility

Basic technical parameters are the first considerations when selecting a diamond drill bit, as they determine whether the bit will fit the intended 钻机，reach the required drilling depth, and match the target hole size. These parameters are universal across all diamond drill bit types (e.g., core bits, straight bits, tile bits) and form the backbone of tool compatibility and application suitability.

1.1 Drill Bit Diameter

Drill bit diameter refers to the maximum width of the bit’s cutting section, which directly dictates the size of the hole it creates. Diameters range from micro-sizes (as small as 0.5 mm) for precision electronics to large-scale core bits (over 500 mm) for mining and civil engineering. The diameter is typically measured in millimeters (mm) for global standards, though inches are still used in some regions (e.g., 1/4”, 3/8”). Key considerations for diameter selection include:
  • Application-specific requirements: Micro-diameters (0.5–3 mm) are used for drilling small holes in circuit boards, glass, or gemstones; medium diameters (4–20 mm) are common in construction (e.g., installing wall anchors) and tile work; large diameters (25–500 mm) are reserved for core drilling in concrete (e.g., for pipes, vents, or structural inspections) and mining.
  • 钻机 compatibility: Larger diameters require more powerful rigs (e.g., hydraulic or pneumatic rigs) to handle torque and pressure, while small diameters can be used with handheld electric drills.
  • Material hardness: Harder materials (e.g., granite, reinforced concrete) may require slightly larger diameters than soft materials (e.g., brick) for the same hole size, as diamond wear can reduce effective diameter over time.
For example, a 6 mm diameter diamond bit is ideal for drilling holes in ceramic tiles for bathroom fixtures, while a 150 mm diameter core bit is used to create openings for HVAC ducts in commercial buildings.

1.2 Drill Bit Length

Drill bit length includes two key measurements: total length (from the top of the shank to the tip of the cutting section) and effective drilling length (the portion of the bit that contacts the material and creates the hole). Total lengths range from 50 mm (for micro-bits) to over 1,000 mm (for deep-hole mining bits), while effective lengths typically account for 60–80% of total length.
  • Effective drilling length: Determines the maximum depth of the hole that can be drilled in a single pass. For example, a bit with a 100 mm effective length can drill holes up to 100 mm deep without repositioning.
  • Total length: Impacts maneuverability. Shorter bits (50–150 mm) are easier to control in tight spaces (e.g., under sinks), while longer bits (200–1,000 mm) are needed for deep holes (e.g., drilling through thick concrete walls).
  • Length-to-diameter ratio: A critical factor for stability. Bits with a high ratio (e.g., a 200 mm long bit with a 6 mm diameter) are more prone to bending or vibrating, which can reduce hole precision. These bits often require guide sleeves or stabilizing attachments to maintain accuracy.

1.3 Shank Type and Size

The shank is the non-cutting section of the drill bit that connects to the drill’s chuck or spindle. Its type and size ensure secure attachment and torque transfer, making compatibility with the 钻机 a top priority. Common shank types for diamond drill bits include:
  • Straight shank: A cylindrical shank with no grooves, used with standard three-jaw chucks (common in handheld electric drills). Sizes are measured by diameter (e.g., 6 mm, 8 mm) or imperial equivalents (e.g., 1/4”, 3/8”). Straight shanks are ideal for small to medium diameter bits (up to 20 mm) and low-torque applications (e.g., tile drilling).
  • SDS shank: A proprietary shank design (developed by Bosch) with grooves that lock into SDS-compatible chucks, providing superior torque transfer and shock resistance. SDS shanks are divided into sub-types:
    • SDS-plus: Used for medium-duty bits (up to 25 mm diameter) in concrete and masonry, compatible with most consumer and professional handheld rigs.
    • SDS-max: For heavy-duty bits (25–100 mm diameter) in reinforced concrete, designed for high-torque rigs (e.g., demolition drills).
    • SDS-top: For large core bits (over 100 mm diameter), used in industrial rigs for deep-hole drilling.
  • Threaded shank: Features external threads (e.g., M14, M20) that screw into compatible spindles, common in core bits for mining and large-scale construction. Threaded shanks ensure a secure connection for high-pressure, high-torque operations.
  • Flange shank: Has a flange (a circular collar) that distributes pressure and prevents the bit from slipping too far into the chuck. Used in heavy-duty core bits for tunnel boring and infrastructure projects.
Shank size must match the 钻机’s chuck or spindle size exactly—using an incompatible shank can lead to slippage, reduced drilling efficiency, or even tool damage. For example, a Bosch SDS-plus bit will not fit a drill with a standard three-jaw chuck unless an adapter is used.

1.4 Working Pressure

Working pressure (also called feed pressure) is the force applied to the drill bit to push it into the material during drilling. It is measured in bars (bar) or pounds per square inch (psi), with typical ranges from 1 bar (14.5 psi) for soft materials (e.g., tile) to 25 bar (362 psi) for hard rock (e.g., granite, basalt).
  • Impact on performance: Too little pressure results in slow drilling speed, as the diamond particles cannot fully engage with the material. Too much pressure causes excessive wear on the diamond layer, leading to premature bit failure and potential damage to the 钻机 (e.g., overheating motors).
  • Material-dependent adjustment: Soft materials (brick, limestone) require lower pressure (1–5 bar) to avoid chipping or cracking. Hard materials (reinforced concrete, quartz) need higher pressure (8–20 bar) to ensure the diamonds penetrate the surface.
  • Diameter correlation: Larger diameter bits require higher pressure to maintain consistent cutting. For example, a 10 mm bit may use 3–5 bar, while a 100 mm core bit may need 10–15 bar.
Most professional 钻机 s have pressure gauges or adjustable settings to help operators maintain the optimal working pressure for the selected bit and material.

1.5 Rotational Speed

Rotational speed (or RPM, revolutions per minute) is the number of times the drill bit spins per minute. It directly affects drilling efficiency and bit life, with ranges from 50 RPM (for large core bits in hard rock) to 30,000 RPM (for micro-bits in glass or ceramics).
  • Inverse relationship with diameter: Larger bits require lower speeds to prevent overheating and diamond wear. A 200 mm core bit may operate at 50–150 RPM, while a 3 mm micro-bit can run at 10,000–30,000 RPM. This is because larger bits have a greater surface area in contact with the material, generating more friction and heat.
  • Material impact: Abrasive materials (e.g., concrete with sand aggregates) require lower speeds (100–500 RPM) to reduce wear, while non-abrasive materials (e.g., glass, plastic) can handle higher speeds (5,000–20,000 RPM).
  • Speed-pressure balance: Higher speeds often require lower pressure to avoid overheating, and vice versa. For example, a 6 mm tile bit may run at 15,000 RPM with 1–2 bar pressure, while a 50 mm concrete core bit runs at 300 RPM with 8–10 bar pressure.
Leading drill manufacturers (e.g., Hilti, DeWalt) provide speed charts for their diamond bits, specifying the optimal RPM range for different materials and diameters to maximize performance and longevity.

2. Performance-Related Technical Parameters: Defining Efficiency and Durability

Performance parameters measure how well a diamond drill bit performs in real-world use, including how fast it drills, how long it lasts, and how well it resists wear. These parameters are closely tied to the bit’s material composition and structural design, making them critical for evaluating tool quality.

2.1 Drilling Efficiency

Drilling efficiency is the rate at which the bit creates holes, typically measured in millimeters per minute (mm/min) or meters per hour (m/h). It is the most direct indicator of a bit’s ability to save time and labor.
  • Key influencing factors:
    • Diamond type and quality: Natural diamond (ND) bits offer higher efficiency than synthetic diamond bits in hard materials, while polycrystalline diamond (PCD) bits are more efficient in soft to medium-hard materials.
    • Diamond concentration: Higher concentration (more diamond particles) increases efficiency in hard materials, as more cutting edges engage with the material.
    • Rotational speed and pressure: Optimal speed-pressure combinations (as discussed in Section 1) maximize efficiency—misalignment of these parameters can reduce speed by 50% or more.
    • Cooling and 排屑: Effective cooling (removing heat) and 排屑 (clearing debris) prevent clogging and maintain consistent cutting. A bit with poor 排屑 may see efficiency drop by 30% after just a few minutes of use.
For example, a high-quality PCD diamond bit may drill through 50 mm of concrete at 10 mm/min, while a lower-quality synthetic diamond bit may take 20 mm/min for the same task. In mining applications, efficiency can reach 1–2 m/h for large core bits in soft rock, but drop to 0.1–0.5 m/h in hard granite.

2.2 Service Life

Service life is the total amount of use a diamond drill bit can withstand before it needs replacement, typically measured in drilled meters (m) or operating hours. It varies widely based on application, material, and bit quality—from a few meters for a low-cost tile bit to hundreds of meters for a premium mining core bit.
  • Primary wear mechanisms:
    • Diamond abrasion: The diamond particles wear down as they cut through abrasive materials (e.g., concrete with sand). This is the most common cause of bit failure.
    • Diamond detachment: Poor bond strength between diamond and the matrix (the metal alloy holding the diamonds) causes diamonds to fall out, reducing cutting ability.
    • Matrix wear: The matrix erodes over time, exposing new diamond particles—but excessive matrix wear can lead to premature diamond loss.
  • Service life examples:
    • Consumer-grade tile bits (6–10 mm diameter): 1–5 meters of drilling in ceramic tile.
    • Professional concrete bits (10–25 mm diameter): 10–50 meters in standard concrete.
    • Industrial mining core bits (100–200 mm diameter): 100–500 meters in soft to medium-hard rock.
Service life can be extended by 20–50% through proper maintenance, such as regular cleaning, using the correct cooling system, and avoiding overpressure or overspeeding.

2.3 Wear Resistance

Wear resistance refers to the bit’s ability to resist damage from friction and abrasion, directly impacting service life. It is measured using standardized tests (e.g., ASTM D7400, which evaluates wear rate in concrete) and is often expressed as volume loss per unit of drilling distance (mm³/m).
  • Material drivers of wear resistance:
    • Diamond hardness: Natural diamond (HV 10,000–12,000) has higher wear resistance than synthetic diamond (HV 6,000–8,000) or PCD (HV 8,000–10,000).
    • Matrix hardness: The matrix (typically copper, iron, or cobalt alloy) must be hard enough to support the diamonds but soft enough to erode gradually and expose new diamonds. Iron-based matrices (HV 300–500) offer higher wear resistance than copper-based matrices (HV 150–250), making them ideal for hard, abrasive materials.
    • Diamond bonding: Stronger bonds between diamonds and the matrix prevent premature diamond loss, a major contributor to wear.
For example, a cobalt-based matrix bit with natural diamonds may have a wear rate of 0.1 mm³/m in granite, while a copper-based matrix bit with synthetic diamonds may have a wear rate of 0.5 mm³/m in the same material. This means the cobalt-based bit will last 5 times longer for the same drilling task.

2.4 Cooling Requirement

Cooling is critical for diamond drill bits, as friction during drilling generates extreme heat (temperatures can exceed 500°C). Excess heat damages the diamond layer (diamond oxidizes at 600°C) and weakens the matrix, leading to premature failure. Cooling requirements are defined by cooling method and coolant flow rate.
  • Cooling methods:
    • Wet cooling: The most common method, using water or water-based coolants (often with additives to prevent rust and improve lubrication). Wet cooling removes heat and flushes away debris, reducing wear by 30–50% compared to dry cooling.
    • Dry cooling: Uses compressed air to blow away debris and cool the bit. It is used in applications where water is prohibited (e.g., electrical work, indoor areas with no drainage) but results in 20–30% shorter service life due to higher heat buildup.
    • Mist cooling: A hybrid method that sprays a fine mist of coolant, combining the efficiency of wet cooling with lower water usage. Ideal for tight spaces or mobile applications.
  • Coolant flow rate: Measured in liters per minute (L/min), it varies by bit size and application. Small bits (3–10 mm) require 2–5 L/min, medium bits (10–50 mm) need 5–15 L/min, and large core bits (50–200 mm) require 15–50 L/min. Insufficient flow (e.g., 1 L/min for a 50 mm bit) can cause the bit to overheat in minutes, while excessive flow (e.g., 60 L/min for a 10 mm bit) wastes coolant and reduces visibility.
Leading brands (e.g., Hilti, Atlas Copco) integrate cooling systems into their 钻机 s, with adjustable flow rates to match specific bit requirements.

3. Structural Technical Parameters: Design Features That Shape Performance

Structural parameters refer to the physical design of the diamond drill bit, including the arrangement of diamonds, the shape of the cutting section, and the design of 排屑 channels. These features directly influence how the bit cuts, cools, and removes debris, making them key differentiators between low- and high-performance tools.

3.1 Diamond Layer Thickness

The diamond layer (or “cutting layer”) is the outer section of the bit that contains the diamond particles. Its thickness ranges from 0.5 mm (for micro-bits) to 5 mm (for heavy-duty mining bits) and determines how much wear the bit can withstand before the matrix is exposed.
  • Thickness considerations:
    • Thin layers (0.5–1 mm): Used in precision applications (e.g., glass, electronics) where minimal material removal is needed. Thin layers offer high precision but short service life.
    • Medium layers (1–2 mm): Ideal for general-purpose use (e.g., tile, brick) and balance precision and durability.
    • Thick layers (2–5 mm): Reserved for heavy-duty applications (e.g., mining, reinforced concrete) where long service life is critical. Thick layers can withstand extensive wear but may be less precise due to increased bit rigidity.
The diamond layer is applied using different methods: sintering (heating diamond and matrix powder under pressure), electroplating (depositing a thin layer of diamond onto a metal core via electrolysis), or bonding (gluing diamond segments to the bit body). Sintered layers are thicker and more durable, while electroplated layers are thinner and more precise.

3.2 Diamond Concentration

Diamond concentration is the volume percentage of diamond particles in the cutting layer, standardized by the American National Standards Institute (ANSI) from 25% to 150%. A concentration of 100% means 1 carat of diamond is present in 1 cm³ of the matrix.
  • Concentration selection guidelines:
    • Low concentration (25–50%): Used for soft materials (e.g., limestone, brick) where fewer cutting edges are needed. Low concentration reduces cost and prevents the bit from “glazing” (diamonds becoming smooth due to insufficient material abrasion).
    • Medium concentration (75–100%): For general-purpose use (e.g., standard concrete, marble). Balances cutting efficiency and cost.
    • High concentration (125–150%): For hard, abrasive materials (e.g., granite, reinforced concrete, basalt). More diamonds mean more cutting edges, reducing wear and increasing efficiency.
Concentration is often marked on the bit (e.g., “100%”) or specified in product datasheets. For example, a Hilti core bit for granite may have a concentration of 150%, while a Bosch tile bit for ceramic may have a concentration of 50%.

3.3 Matrix Material

The matrix is the metal alloy that holds the diamond particles in place, acting as both a support structure and a gradual wear medium (it erodes to expose new diamonds). The choice of matrix material depends on the target material and desired service life. Common matrix materials include:
  • Copper-based alloys: Composed of copper (60–80%) with additives (tin, zinc, nickel). They have low hardness (HV 150–250), good thermal conductivity, and erode quickly. Ideal for soft to medium-hard materials (e.g., tile, brick, limestone) and low-abrasion applications. Copper-based matrices are cost-effective and widely used in consumer-grade bits.
  • Iron-based alloys: Contain iron (70–90%) with additives (carbon, chromium, manganese). They have high hardness (HV 300–500) and wear resistance, making them suitable for hard, abrasive materials (e.g., concrete, granite). Iron-based matrices erode slowly, providing long service life but requiring higher pressure to expose new diamonds.
  • Cobalt-based alloys: The premium option, with cobalt (50–70%) and additives (tungsten, carbide). They offer the highest hardness (HV 400–600) and thermal stability, making them ideal for extreme applications (e.g., mining hard rock, drilling through reinforced steel). Cobalt-based matrices have excellent bond strength with diamonds but are expensive (2–3 times the cost of copper-based matrices).
Matrix composition is a key proprietary feature for brands—for example, DeWalt’s “Tough Matrix” for concrete bits uses a copper-iron alloy to balance durability and cost, while Atlas Copco’s mining bits use cobalt-based matrices for maximum wear resistance.

3.4 Drill Bit Design Type

Diamond drill bits are classified by their design type, which determines their suitability for specific materials and drilling methods. The three main types are:

3.4.1 Impregnated Diamond Drill Bits

Impregnated bits have diamond particles evenly distributed (impregnated) throughout the matrix layer. As the matrix erodes, new diamonds are continuously exposed, making them ideal for long, continuous drilling in hard materials.
  • Design features: Thick matrix layer (1–5 mm), medium to high diamond concentration (75–150%), and a smooth cutting surface.
  • Applications: Hard rock mining (granite, basalt), reinforced concrete, and geological exploration.
  • Advantages: Long service life, consistent performance, and ability to handle abrasive materials.
  • Disadvantages: Slower initial drilling speed (until the first layer of diamonds is exposed) and higher cost.

3.4.2 Surface-Set Diamond Drill Bits

Surface-set bits have diamond particles bonded to the surface of the matrix (not embedded), creating a sharp, aggressive cutting edge. They are designed for fast drilling in soft to medium-hard materials.
  • Design features: Thin matrix layer (0.5–1 mm), low to medium concentration (25–75%), and protruding diamond particles.
  • Applications: Soft rock (limestone, sandstone), brick, and non-abrasive concrete.
  • Advantages: High initial drilling speed, low cost, and easy sharpening (via light grinding).
  • Disadvantages: Short service life (diamonds wear or fall out quickly) and poor performance in abrasive materials.

3.4.3 Electroplated Diamond Drill Bits

Electroplated bits use an electrolytic process to deposit a thin layer of diamond (0.1–0.5 mm) onto a metal core (usually steel). The diamond layer is held in place by a nickel bond, creating a precise, smooth cutting surface.
  • Design features: Ultra-thin diamond layer, high concentration (100–150%), and a rigid steel core.
  • Applications: Precision drilling (glass, ceramics, gemstones), electronics (circuit boards), and decorative stone work.
  • Advantages: High precision (can drill holes with tolerances of ±0.01 mm), smooth hole surfaces, and ability to cut non-metallic materials without chipping.
  • Disadvantages: Very short service life (diamond layer wears quickly), unsuitable for abrasive materials, and cannot be resharpened.

3.5 Waterway and Chip Removal Channel Design

Waterways (for coolant flow) and chip removal channels (for debris evacuation) are critical structural features that prevent clogging, reduce heat, and maintain drilling efficiency. Poorly designed channels can cause the bit to “bind” (get stuck in the hole) or overheat, leading to tool failure.
  • Waterway design:
    • Number of waterways: Small bits (3–10 mm) have 1–2 waterways, medium bits (10–50 mm) have 2–4, and large core bits (50+ mm) have 4–8. More waterways ensure even coolant distribution.
    • Shape and size: Waterways are typically rectangular or circular, with widths ranging from 1 mm (micro-bits) to 10 mm (core bits). Wider waterways allow higher coolant flow but reduce the bit’s structural strength.
    • Position: Waterways are located along the length of the bit, often adjacent to the cutting layer, to direct coolant directly to the cutting surface.
  • Chip removal channel design:
    • Depth and width: Channels must be deep enough to collect debris (typically 2–5 mm deep for medium bits) and wide enough to allow easy evacuation. Narrow channels (less than 1 mm) are prone to clogging with fine debris (e.g., concrete dust).
    • Helix angle: For straight bits, channels are often helical (spiral-shaped) with an angle of 20–40 degrees. This helix helps “lift” debris out of the hole as the bit spins. Core bits use straight or spiral channels, depending on the material—spiral channels are better for fine debris, while straight channels handle large chips (e.g., from brick).
For example, Hilti’s TE-CX concrete bits feature “X-Slot” channels—wide, spiral-shaped channels that improve both coolant flow and debris removal, reducing clogging by 40% compared to standard straight channels.

4. Material-Related Technical Parameters: The Science Behind Diamond and Matrix Performance

The performance of a diamond drill bit is ultimately determined by the quality of its materials—specifically, the type of diamond used, its grain size, and the bond strength between diamonds and the matrix. These parameters are the result of advanced material science and are key to differentiating premium bits from budget options.

4.1 Diamond Type

Diamonds used in drill bits are categorized into three main types, each with unique physical properties and applications:

4.1.1 Natural Diamond (ND)

Natural diamonds are mined from geological formations and are the hardest known material (HV 10,000–12,000). They have high thermal conductivity (2,000 W/m·K) and resistance to oxidation, making them ideal for extreme applications.
  • Properties:
    • Hardness: HV 10,000–12,000 (Mohs 10).
    • Thermal conductivity: 2,000 W/m·K (5 times higher than copper).
    • Oxidation temperature: 600°C (starts to burn in air above this temperature).
  • Applications: Hard rock mining (granite, basalt), drilling through reinforced steel, and high-temperature environments.
  • Advantages: Highest wear resistance and durability, longest service life.
  • Disadvantages: Extremely expensive (10–20 times the cost of synthetic diamond), limited availability, and variable quality (natural diamonds may have inclusions that reduce strength).

4.1.2 Synthetic Diamond (Single-Crystal)

Synthetic single-crystal diamonds are produced in labs using high-pressure, high-temperature (HPHT) processes (pressures of 5–6 GPa, temperatures of 1,500–2,000°C). They have properties similar to natural diamonds but with consistent quality and lower cost.
  • Properties:
    • Hardness: HV 6,000–8,000 (slightly lower than natural diamond).
    • Thermal conductivity: 1,500 W/m·K.
    • Oxidation temperature: 550°C.
  • Applications: General-purpose drilling (concrete, marble), construction, and consumer-grade tools.
  • Advantages: Consistent quality (no inclusions), lower cost than natural diamond, and wide availability.
  • Disadvantages: Lower wear resistance than natural diamond, unsuitable for the hardest materials.

4.1.3 Polycrystalline Diamond (PCD)

PCD is a composite material made by sintering millions of small synthetic diamond grains (1–10 μm) with a cobalt or nickel binder under HPHT conditions. It forms a tough, uniform cutting surface with no single point of failure.
  • Properties:
    • Hardness: HV 8,000–10,000 (between synthetic and natural diamond).
    • Thermal conductivity: 1,800 W/m·K.
    • Oxidation temperature: 500°C (lower than single-crystal diamonds due to the binder).
  • Applications: Soft to medium-hard materials (limestone, brick, aluminum composites), wood with abrasive fillers, and automotive manufacturing (drilling composite parts).
  • Advantages: High toughness (resists chipping), good wear resistance, and lower cost than natural diamond.
  • Disadvantages: Poor performance in high-temperature applications (binder oxidizes quickly) and cannot be resharpened (once worn, the entire PCD layer must be replaced).

4.1.4 Chemical Vapor Deposition (CVD) Diamond

CVD diamond is produced by depositing carbon atoms onto a substrate (e.g., silicon) in a vacuum chamber, creating a pure, high-quality diamond layer. It is the newest type of diamond used in drill bits, offering exceptional purity and precision.
  • Properties:
    • Hardness: HV 9,000–11,000 (close to natural diamond).
    • Thermal conductivity: 2,200 W/m·K (higher than natural diamond).
    • Oxidation temperature: 650°C (highest among all diamond types).
  • Applications: Precision drilling (semiconductors, optical glass), aerospace (drilling composite materials), and medical devices (drilling bone or ceramics).
  • Advantages: Ultra-pure (no binders or inclusions), high thermal stability, and ability to form thin, precise layers.
  • Disadvantages: Very high cost (5–10 times the cost of PCD), limited to small bits (due to production constraints), and low availability.

4.2 Diamond Grain Size

Diamond grain size refers to the diameter of individual diamond particles in the cutting layer, ranging from fine (1–10 μm) to coarse (100–200 μm). Grain size directly impacts drilling precision and efficiency.
  • Fine grain size (1–20 μm):
    • Characteristics: Small, closely packed particles create a smooth cutting surface.
    • Applications: Precision drilling (glass, ceramics, electronics), where hole surface finish is critical (e.g., drilling holes for fiber optics).
    • Advantages: Produces smooth, burr-free holes with tight tolerances (±0.01 mm).
    • Disadvantages: Lower drilling speed (fewer large cutting edges) and higher cost (fine grains are more expensive to produce).
  • Medium grain size (20–50 μm):
    • Characteristics: Balanced particle size, combining precision and efficiency.
    • Applications: General-purpose drilling (concrete, marble, tile), where both speed and surface quality are important.
    • Advantages: Versatile, cost-effective, and suitable for most consumer and professional applications.
    • Disadvantages: Not ideal for extreme precision or maximum efficiency.
  • Coarse grain size (50–200 μm):
    • Characteristics: Large particles with aggressive cutting edges.
    • Applications: High-efficiency drilling (soft rock, brick, non-abrasive concrete), where speed is prioritized over surface finish.
    • Advantages: Fastest drilling speed (large particles remove more material per revolution) and lower cost (coarse grains are cheaper to produce).
    • Disadvantages: Produces rough hole surfaces (with visible tool marks) and higher wear rate (large particles are more prone to detachment).
Grain size is often specified in product datasheets—for example, a Makita tile bit for glass may use 5 μm fine grains, while an Atlas Copco mining bit for soft rock uses 100 μm coarse grains.

4.3 Bond Strength Between Diamond and Matrix

Bond strength is the force required to separate diamond particles from the matrix, measured in megapascals (MPa) via standardized tests (e.g., shear tests, tensile tests). Strong bonds prevent premature diamond loss, a major cause of bit failure.
  • Key factors influencing bond strength:
    • Matrix composition: Cobalt-based matrices form stronger bonds with diamonds (200–300 MPa) than copper-based matrices (100–150 MPa), as cobalt has a higher affinity for carbon (the main component of diamond).
    • Sintering parameters: For sintered bits, higher pressure (5–8 GPa) and temperature (1,200–1,500°C) improve bond strength by promoting diffusion between diamond and matrix atoms.
    • Diamond surface treatment: Some manufacturers coat diamonds with a thin layer of titanium or chromium to enhance bonding. This treatment can increase bond strength by 30–50%.
    • Grain size: Smaller diamond grains have a larger surface area in contact with the matrix, leading to stronger bonds. For example, 10 μm grains may have a bond strength of 250 MPa, while 100 μm grains have 180 MPa.
  • Bond strength examples:
    • Electroplated bits: Bond strength is relatively low (50–100 MPa), as diamonds are held in place by a nickel layer rather than atomic diffusion. This is why electroplated bits have short service lives.
    • Sintered PCD bits: Bond strength ranges from 150–200 MPa, suitable for medium-duty applications.
    • Sintered natural diamond bits: Bond strength can exceed 300 MPa, making them ideal for heavy-duty mining and hard rock drilling.
Leading brands invest heavily in bond strength research—for example, Bosch’s “Diamond Fusion Technology” uses a proprietary sintering process to increase bond strength by 40%, while Hilti’s “CVD Bond” for precision bits uses a titanium coating to enhance diamond-matrix adhesion.

5. Leading Brands and Their Typical Models: Detailed Specifications and Applications

The global diamond drill bit market is dominated by a few key brands, each offering specialized products for consumer, professional, and industrial applications. Below is a detailed breakdown of leading brands, their flagship models, and the technical parameters that make each model suitable for specific tasks.

5.1 Bosch (Germany): Consumer and Professional-Grade Bits

Bosch is a leading manufacturer of power tools and accessories, with a wide range of diamond drill bits for construction, home improvement, and light industrial use. Their bits are known for affordability, reliability, and compatibility with most standard 钻机 s.

5.1.1 Model: Bosch Professional Diamond Drill Bit for Concrete – 2608595067

This is a medium-duty impregnated diamond bit designed for drilling in concrete, masonry, and brick. It is part of Bosch’s “Professional” line, targeting contractors and DIY enthusiasts.
  • Basic parameters:
    • Diameter: 10 mm
    • Total length: 150 mm
    • Effective drilling length: 100 mm
    • Shank type: SDS-plus (compatible with most Bosch, DeWalt, and Makita SDS-plus 钻机 s)
    • Working pressure: 3–5 bar
    • Rotational speed: 800–1,500 RPM
  • Performance parameters:
    • Drilling efficiency: 8–10 mm/min in standard concrete (C25/C30 grade)
    • Service life: 15–25 meters in concrete
    • Wear resistance: 0.3 mm³/m (ASTM D7400 test in concrete)
    • Cooling requirement: Wet cooling (2–5 L/min flow rate)
  • Structural and material parameters:
    • Diamond type: Synthetic single-crystal diamond
    • Diamond concentration: 100%
    • Matrix material: Copper-iron alloy (60% copper, 30% iron, 10% nickel)
    • Diamond layer thickness: 1.5 mm
    • Waterway design: 2 rectangular waterways (2 mm width)
    • Chip removal channels: Spiral helix (30° angle, 3 mm depth)
  • Applications: Installing wall anchors, drilling holes for electrical boxes, and general concrete repair.
  • Advantages: SDS-plus shank for secure torque transfer, copper-iron matrix for balanced durability, and spiral channels for efficient debris removal.
  • Disadvantages: Not suitable for reinforced concrete (diamond wear is excessive) or hard rock.

5.1.2 Model: Bosch Professional Diamond Core Drill Bit – 2608595103

This is a heavy-duty core bit for large-diameter holes in concrete, stone, and masonry. It is designed for commercial construction (e.g., pipe installation, HVAC ducting) and uses a sintered PCD cutting layer.
  • Basic parameters:
    • Diameter: 50 mm (core hole diameter; outer diameter of the bit is 55 mm)
    • Total length: 350 mm
    • Effective drilling length: 250 mm
    • Shank type: SDS-max (for high-torque rigs)
    • Working pressure: 5–8 bar
    • Rotational speed: 300–800 RPM
  • Performance parameters:
    • Drilling efficiency: 5–7 mm/min in reinforced concrete (C30/C35 grade)
    • Service life: 50–80 meters in concrete
    • Wear resistance: 0.2 mm³/m (ASTM D7400 test in reinforced concrete)
    • Cooling requirement: Wet cooling (15–20 L/min flow rate)
  • Structural and material parameters:
    • Diamond type: PCD (polycrystalline diamond)
    • Diamond concentration: 120%
    • Matrix material: Iron-based alloy (80% iron, 15% chromium, 5% carbon)
    • Diamond layer thickness: 2.5 mm
    • Waterway design: 4 circular waterways (5 mm width)
    • Chip removal channels: Straight channels (8 mm depth, 10 mm width)
  • Applications: Drilling holes for water pipes, electrical conduits, and HVAC vents in commercial buildings.
  • Advantages: SDS-max shank for heavy-duty torque, iron-based matrix for high wear resistance, and large waterways for effective cooling.
  • Disadvantages: Heavy (1.2 kg) and less maneuverable, requiring a stand-mounted 钻机.

5.2 DeWalt (USA): Professional-Grade Construction Bits

DeWalt is a leading brand in professional power tools, known for rugged, durable diamond bits designed for construction, demolition, and industrial use. Their bits focus on high performance and long service life.

5.2.1 Model: DeWalt DW5470 Diamond Drill Bit for Masonry

This is a surface-set diamond bit for drilling in masonry, brick, and soft concrete. It is part of DeWalt’s “Masonry” line, targeting contractors and tradespeople.
  • Basic parameters:
    • Diameter: 8 mm
    • Total length: 120 mm
    • Effective drilling length: 80 mm
    • Shank type: Straight shank (3/8” diameter, compatible with standard three-jaw chucks)
    • Working pressure: 2–4 bar
    • Rotational speed: 1,000–2,000 RPM
  • Performance parameters:
    • Drilling efficiency: 12–15 mm/min in brick
    • Service life: 10–15 meters in masonry
    • Wear resistance: 0.4 mm³/m (ASTM D7400 test in brick)
    • Cooling requirement: Wet or dry cooling (dry cooling reduces service life by 30%)
  • Structural and material parameters:
    • Diamond type: Synthetic single-crystal diamond
    • Diamond concentration: 90%
    • Matrix material: Copper-based alloy (70% copper, 20% tin, 10% zinc)
    • Diamond layer thickness: 1 mm
    • Waterway design: 1 rectangular waterway (1.5 mm width)
    • Chip removal channels: Spiral helix (25° angle, 2 mm depth)
  • Applications: Drilling holes for masonry screws, installing outdoor fixtures, and repairing brick walls.
  • Advantages: Straight shank for compatibility with most handheld drills, low cost, and dual cooling options (wet/dry).
  • Disadvantages: Short service life in abrasive materials (e.g., concrete with sand aggregates) and prone to diamond detachment in high-pressure use.

5.2.2 Model: DeWalt DWA5427 Core Drill Bit

This is an industrial-grade core bit for heavy-duty drilling in reinforced concrete, granite, and hard rock. It uses a cobalt-based matrix and natural diamond particles for maximum durability.
  • Basic parameters:
    • Diameter: 100 mm (core hole diameter; outer diameter 108 mm)
    • Total length: 450 mm
    • Effective drilling length: 350 mm
    • Shank type: Threaded shank (M14, compatible with DeWalt’s D21570 core drill rig)
    • Working pressure: 6–10 bar
    • Rotational speed: 200–500 RPM
  • Performance parameters:
    • Drilling efficiency: 3–5 mm/min in granite
    • Service life: 100–150 meters in reinforced concrete
    • Wear resistance: 0.1 mm³/m (ASTM D7400 test in granite)
    • Cooling requirement: Wet cooling (20–25 L/min flow rate, with rust inhibitor additive)
  • Structural and material parameters:
    • Diamond type: Natural diamond (ND)
    • Diamond concentration: 130%
    • Matrix material: Cobalt-based alloy (60% cobalt, 25% tungsten, 15% carbon)
    • Diamond layer thickness: 3 mm
    • Waterway design: 6 circular waterways (6 mm width)
    • Chip removal channels: Spiral channels (45° angle, 10 mm depth)
  • Applications: Industrial construction (bridge repair, tunnel boring), mining exploration, and heavy-duty concrete drilling.
  • Advantages: Natural diamonds for extreme wear resistance, cobalt-based matrix for high bond strength, and large spiral channels for efficient debris removal.
  • Disadvantages: Very high cost (3–4 times the cost of PCD bits) and requires a specialized core drill rig.

5.3 Hilti (Liechtenstein): Industrial-Grade Precision Bits

Hilti is a global leader in industrial construction tools, specializing in high-performance diamond bits for extreme applications (e.g., reinforced concrete, hard rock, precision drilling). Their bits are known for innovative design and advanced materials.

5.3.1 Model: Hilti TE-CX Diamond Drill Bit – 326072

This is a precision impregnated diamond bit for drilling in reinforced concrete, high-strength concrete (C40/C50 grade), and steel-reinforced masonry. It uses CVD diamond particles for enhanced durability.
  • Basic parameters:
    • Diameter: 12 mm
    • Total length: 160 mm
    • Effective drilling length: 110 mm
    • Shank type: TE-C (Hilti’s proprietary shank, compatible with Hilti TE 30/40/50 钻机 s)
    • Working pressure: 4–6 bar
    • Rotational speed: 700–1,600 RPM
  • Performance parameters:
    • Drilling efficiency: 7–9 mm/min in reinforced concrete
    • Service life: 30–40 meters in high-strength concrete
    • Wear resistance: 0.15 mm³/m (ASTM D7400 test in C40 concrete)
    • Cooling requirement: Wet or mist cooling (mist cooling uses 50% less water than wet cooling)
  • Structural and material parameters:
    • Diamond type: CVD diamond
    • Diamond concentration: 110%
    • Matrix material: Cobalt-copper alloy (50% cobalt, 40% copper, 10% nickel)
    • Diamond layer thickness: 2 mm
    • Waterway design: 2 spiral waterways (3 mm width)
    • Chip removal channels: “X-Slot” design (patented by Hilti, 4 mm depth, 5 mm width)
  • Applications: Precision drilling in high-strength concrete (e.g., skyscraper columns), installing anchor bolts in reinforced structures, and electrical work in industrial buildings.
  • Advantages: CVD diamond for high thermal stability, TE-C shank for secure attachment, and X-Slot channels for reduced clogging (40% better than standard channels).
  • Disadvantages: Limited compatibility (only with Hilti 钻机 s) and high cost.

5.3.2 Model: Hilti DD 120-U Diamond Core Drill Bit

This is a large-scale core bit for industrial drilling in concrete, granite, and hard rock. It is designed for tunnel boring, mining exploration, and infrastructure projects (e.g., dam repair).
  • Basic parameters:
    • Diameter: 120 mm (core hole diameter; outer diameter 130 mm)
    • Total length: 500 mm
    • Effective drilling length: 400 mm
    • Shank type: DD-B (Hilti’s proprietary flange shank, compatible with Hilti DD 200-U core drill rig)
    • Working pressure: 8–12 bar
    • Rotational speed: 250–600 RPM
  • Performance parameters:
    • Drilling efficiency: 4–6 mm/min in granite
    • Service life: 200–300 meters in hard rock
    • Wear resistance: 0.08 mm³/m (ASTM D7400 test in basalt)
    • Cooling requirement: Wet cooling (25–30 L/min flow rate, with thermal stabilizer additive)
  • Structural and material parameters:
    • Diamond type: Natural diamond (ND)
    • Diamond concentration: 140%
    • Matrix material: Cobalt-iron alloy (70% cobalt, 25% iron, 5% tungsten)
    • Diamond layer thickness: 4 mm
    • Waterway design: 8 circular waterways (8 mm width)
    • Chip removal channels: Straight, wide channels (12 mm depth, 15 mm width)
  • Applications: Tunnel boring, mining exploration (core sampling), dam and bridge repair, and large-scale pipe installation.
  • Advantages: Natural diamonds for maximum wear resistance, flange shank for stability in heavy-duty rigs, and wide channels for handling large debris (e.g., rock chips up to 10 mm).
  • Disadvantages: Extremely heavy (3.5 kg), requires a hydraulic or pneumatic rig, and very high cost (only viable for industrial projects).

5.4 Makita (Japan): Consumer and Light Professional Bits

Makita is a leading manufacturer of power tools, offering a range of diamond bits for home improvement, tile work, and light construction. Their bits are known for compact design and compatibility with Makita’s handheld 钻机 s.

5.4.1 Model: Makita D-23943 Diamond Drill Bit for Tile

This is an electroplated diamond bit for precision drilling in ceramic tile, glass, and porcelain. It is designed for bathroom and kitchen renovations (e.g., installing faucets, showerheads).
  • Basic parameters:
    • Diameter: 6 mm
    • Total length: 80 mm
    • Effective drilling length: 50 mm
    • Shank type: Straight shank (1/4” diameter, compatible with Makita HP1640/HP1840 钻机 s)
    • Working pressure: 1–3 bar
    • Rotational speed: 1,500–3,000 RPM
  • Performance parameters:
    • Drilling efficiency: 3–5 mm/min in ceramic tile
    • Service life: 5–8 meters in glass
    • Wear resistance: 0.5 mm³/m (ASTM D7400 test in porcelain)
    • Cooling requirement: Wet cooling (1–2 L/min flow rate, using distilled water to prevent mineral deposits)
  • Structural and material parameters:
    • Diamond type: Electroplated synthetic diamond
    • Diamond concentration: 80%
    • Matrix material: Nickel bond (electroplated onto a steel core)
    • Diamond layer thickness: 0.3 mm
    • Waterway design: 1 small circular waterway (1 mm width)
    • Chip removal channels: Micro-helix (40° angle, 0.5 mm depth)
  • Applications: Drilling holes in ceramic tile for faucets, glass shelves, and porcelain sinks.
  • Advantages: Electroplated diamond for precision (no chipping), compact design for tight spaces (e.g., under sinks), and compatibility with standard handheld drills.
  • Disadvantages: Very short service life (cannot be resharpened) and unsuitable for abrasive materials.

5.4.2 Model: Makita D-45932 Core Drill Bit

This is a medium-duty core bit for drilling in concrete, stone, and masonry. It is designed for light commercial construction (e.g., retail store renovations) and uses a sintered PCD cutting layer.
  • Basic parameters:
    • Diameter: 80 mm (core hole diameter; outer diameter 88 mm)
    • Total length: 400 mm
    • Effective drilling length: 300 mm
    • Shank type: SDS-plus (compatible with Makita HR2630/HR2641 钻机 s)
    • Working pressure: 5–7 bar
    • Rotational speed: 400–900 RPM
  • Performance parameters:
    • Drilling efficiency: 6–8 mm/min in standard concrete
    • Service life: 60–90 meters in concrete
    • Wear resistance: 0.25 mm³/m (ASTM D7400 test in concrete)
    • Cooling requirement: Wet cooling (18–22 L/min flow rate)
  • Structural and material parameters:
    • Diamond type: PCD (polycrystalline diamond)
    • Diamond concentration: 120%
    • Matrix material: Copper-iron alloy (50% copper, 40% iron, 10% chromium)
    • Diamond layer thickness: 2 mm
    • Waterway design: 4 rectangular waterways (4 mm width)
    • Chip removal channels: Spiral channels (35° angle, 6 mm depth)
  • Applications: Drilling holes for electrical conduits, HVAC vents, and display cases in retail stores.
  • Advantages: SDS-plus shank for compatibility with handheld rigs, copper-iron matrix for balanced durability, and spiral channels for efficient debris removal.
  • Disadvantages: Not suitable for hard rock (e.g., granite) and requires a stand for stability in deep drilling.

5.5 Atlas Copco (Sweden): Industrial Mining and Heavy-Duty Bits

Atlas Copco is a global leader in industrial equipment, specializing in diamond drill bits for mining, oil and gas exploration, and large-scale infrastructure projects. Their bits are engineered for extreme durability and high efficiency in harsh environments.

5.5.1 Model: Atlas Copco ROC D7 Diamond Drill Bit for Mining

This is a heavy-duty impregnated diamond bit for mining and hard rock exploration. It is designed for use with Atlas Copco’s ROC D7 surface drill rigs and targets soft to medium-hard rock (e.g., limestone, sandstone).
  • Basic parameters:
    • Diameter: 115 mm
    • Total length: 600 mm
    • Effective drilling length: 500 mm
    • Shank type: Threaded shank (API standard, compatible with ROC D7 rigs)
    • Working pressure: 15–20 bar
    • Rotational speed: 150–300 RPM
  • Performance parameters:
    • Drilling efficiency: 1–2 m/h in soft rock (limestone)
    • Service life: 100–200 meters in medium-hard rock
    • Wear resistance: 0.12 mm³/m (ASTM D7400 test in sandstone)
    • Cooling requirement: Wet cooling (30–40 L/min flow rate, with dust suppression additive)
  • Structural and material parameters:
    • Diamond type: Synthetic single-crystal diamond
    • Diamond concentration: 150%
    • Matrix material: Iron-based alloy (85% iron, 10% carbon, 5% manganese)
    • Diamond layer thickness: 3.5 mm
    • Waterway design: 6 spiral waterways (7 mm width)
    • Chip removal channels: Wide straight channels (15 mm depth, 20 mm width)
  • Applications: Surface mining (coal, limestone), mineral exploration (core sampling), and quarrying.
  • Advantages: High diamond concentration for fast drilling, iron-based matrix for wear resistance, and large channels for handling mining debris (e.g., rock fragments up to 20 mm).
  • Disadvantages: Requires a large surface drill rig and is not suitable for hard rock (e.g., granite).

5.5.2 Model: Atlas Copco COP 1838 Diamond Core Bit

This is an industrial-grade core bit for deep-hole drilling in hard rock (e.g., granite, basalt) and oil/gas exploration. It uses natural diamond particles and a cobalt-based matrix for maximum durability.
  • Basic parameters:
    • Diameter: 200 mm (core hole diameter; outer diameter 210 mm)
    • Total length: 800 mm
    • Effective drilling length: 650 mm
    • Shank type: Flange shank (Atlas Copco proprietary, compatible with COP 1838 rigs)
    • Working pressure: 20–25 bar
    • Rotational speed: 100–250 RPM
  • Performance parameters:
    • Drilling efficiency: 0.5–1 m/h in granite
    • Service life: 300–500 meters in hard rock
    • Wear resistance: 0.05 mm³/m (ASTM D7400 test in basalt)
    • Cooling requirement: Wet cooling (40–50 L/min flow rate, with high-temperature stabilizer)
  • Structural and material parameters:
    • Diamond type: Natural diamond (ND)
    • Diamond concentration: 160%
    • Matrix material: Cobalt-tungsten alloy (75% cobalt, 20% tungsten, 5% carbon)
    • Diamond layer thickness: 5 mm
    • Waterway design: 8 circular waterways (10 mm width)
    • Chip removal channels: Heavy-duty straight channels (20 mm depth, 25 mm width)
  • Applications: Deep-hole mining exploration, oil and gas well drilling (core sampling), and tunnel boring in hard rock.
  • Advantages: Natural diamonds for extreme wear resistance, cobalt-tungsten matrix for high bond strength, and heavy-duty channels for handling large rock debris.
  • Disadvantages: Extremely expensive (only viable for industrial projects), requires a hydraulic rig, and is not portable.

6. Conclusion: Selecting the Right Diamond Drill Bit Based on Technical Parameters

Selecting the correct diamond drill bit requires a clear understanding of technical parameters and their alignment with the application. The key steps in selection are:
  1. Define the application: Identify the target material (e.g., concrete, glass, granite), required hole size (diameter), and depth (effective length).
  2. Match basic parameters: Choose the appropriate diameter, length, and shank type to fit the 钻机 and application. For example, a handheld drill for tile work requires a small diameter (6 mm), short length (80 mm), and straight shank.
  3. Optimize performance parameters: Adjust working pressure and rotational speed based on material hardness—hard materials need higher pressure and lower speed, while soft materials need lower pressure and higher speed.
  4. Select structural and material features: Choose the right diamond type (natural for hard rock, PCD for general use, electroplated for precision), concentration (high for hard materials), and matrix (cobalt for durability, copper for cost).
  5. Consider brand and model: Select a reputable brand (e.g., Hilti for industrial use, Bosch for consumer use) with a model that matches the technical requirements.
By following these steps, users can maximize drilling efficiency, extend tool life, and avoid costly mistakes (e.g., using a consumer-grade bit in hard rock). Leading brands provide detailed datasheets with all technical parameters, making it easy to compare models and select the best tool for the job.
As diamond drill bit technology continues to advance—with innovations like CVD diamond, 3D-printed matrices, and smart sensors (for real-time temperature/pressure monitoring)—technical parameters will become even more precise, enabling higher performance in extreme applications. Whether for home improvement, construction, or mining, understanding these parameters remains the foundation of successful drilling.

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