Solid Carbide Standard Drill Bits GD Series | 1-20mm Coolant Through Drill
High-performance solid carbide drills with internal coolant, 3XD/5XD/8XD options, and 1–20mm diameters for CNC machining.
Product Introduction
Solid Carbide Standard Drill Bits GD Series are high-efficiency CNC drilling tools developed for general-purpose metal machining, precision drilling, and automated production. Covering diameters from 1 mm to 20 mm (0.0394"–0.7874"), the GD Series is available in 3XD, 5XD, and 8XD flute-length options for different hole-depth requirements.
Manufactured by CHANGZHOU BOSTONTOOL CO.,LTD., these coolant-through solid carbide drills combine an ultra-fine grain carbide substrate, optimized drill-point geometry, polished flutes, and multi-layer nano composite coating. The design focuses on rigidity, centering accuracy, chip evacuation, wear resistance, and stable performance during continuous CNC machining.
The GD Series is suitable for carbon steel, mold steel, alloy steel, tempered steel, cast iron, and other commonly machined metal materials. It can support both dry cutting and coolant-assisted wet cutting, making it suitable for CNC machining centers, drilling and milling machines, and automated production lines.
Key Product Features
1. Ultra-Fine Grain Carbide Substrate
The GD Series uses an ultra-fine grain carbide substrate designed to provide high rigidity, wear resistance, and thermal stability. The substrate hardness can reach HRC60+, helping the drill withstand high-speed machining and repeated cutting operations.
Compared with conventional drilling tools, the optimized carbide structure is designed to reduce edge chipping, premature wear, and tool replacement frequency, supporting longer tool life in demanding production environments.
2. 140° Drill Point & Optimized Flutes
The 140° apex angle is combined with an optimized helical flute structure to support stable positioning and efficient chip evacuation. Polished flute surfaces help chips move smoothly away from the cutting zone, reducing the possibility of chip accumulation during continuous drilling.
The rigid integral carbide body also helps minimize vibration and maintain drilling stability, particularly when machining deeper holes.
3. Self-Centering Drilling
The drill tip incorporates cross-edge correction and self-centering geometry to improve initial positioning accuracy. For suitable applications, the drill can perform direct drilling without a separate center-drilling operation.
The design helps improve hole consistency, reduce deviation, and achieve finished hole dimensional accuracy up to m7 under appropriate machining conditions.
4. Internal Coolant Through Design
Internal coolant channels deliver cutting fluid directly toward the cutting area. This helps remove heat and chips from the hole while improving cooling efficiency during deep-hole and continuous CNC machining.
The coolant-through structure is particularly useful for automated production and applications involving extended drilling cycles.
5. Multi-Layer Nano Composite Coating
The GD Series can be equipped with TiN, TiCN, or AlTiN nano composite coating options. The coating is designed to provide high hardness, low friction, oxidation resistance, and improved thermal protection.
Depending on the machining material and operating conditions, coating options can help reduce cutting friction and tool wear while supporting both dry and wet cutting applications.
Product Specifications
| Item | Specification |
|---|---|
| Series | GD Series |
| Tool Type | Solid Carbide Standard Drill |
| Diameter Range | 1–20 mm |
| Inch Range | 0.0394"–0.7874" |
| Flute Length | 3XD / 5XD / 8XD |
| Drill Point | 140° |
| Coolant | Internal Coolant Through |
| Cutting | Dry / Wet Cutting |
| Substrate | Ultra-Fine Grain Carbide |
| Substrate Hardness | HRC60+ |
| Coating | TiN / TiCN / AlTiN |
| Applicable Equipment | CNC Machining Centers, CNC Drilling & Milling Machines, Automated Production Lines |
| Main Materials | Carbon Steel, Mold Steel, Alloy Steel, Tempered Steel, Cast Iron |
Standard 3XD Dimensions
| Diameter (mm) | Cutting Length (mm) | Shank (mm) | Overall Length (mm) |
| 1–1.2 | 4 | 4 | 50 |
| 1.3–1.4 | 5 | 4 | 50 |
| 1.5–1.6 | 6 | 4 | 50 |
| 1.7–1.8 | 7 | 4 | 50 |
| 1.9–2.0 | 8 | 4 | 50 |
| 2.1–2.5 | 9–10 | 4 | 50 |
| 2.6–2.9 | 11–12 | 4 | 50 |
| 3.0–3.7 | 20 | 6 | 62 |
| 3.8–4.7 | 24 | 6 | 62 |
| 4.8–6.0 | 28 | 6 | 66 |
| 6.1–8.0 | 34–41 | 8 | 79 |
| 8.1–10.0 | 47 | 10 | 89 |
| 10.1–12.0 | 55 | 12 | 102 |
| 12.1–14.0 | 60 | 14 | 107 |
| 14.1–16.0 | 65 | 16 | 115 |
| 16.1–18.0 | 73 | 18 | 123 |
| 18.1–20.0 | 79 | 20 | 131 |
Standard 5XD Dimensions
| Diameter (mm) | Cutting Length (mm) | Shank (mm) | Overall Length (mm) |
| 1–2.0 | 6–12 | 4 | 50 |
| 2.1–2.9 | 13–17 | 4 | 50 |
| 3.0–3.7 | 28 | 6 | 66 |
| 3.8–4.7 | 36 | 6 | 74 |
| 4.8–6.0 | 44 | 6 | 82 |
| 6.1–8.0 | 53 | 8 | 91 |
| 8.1–10.0 | 61 | 10 | 103 |
| 10.1–12.1 | 71 | 12 | 118 |
| 12.1–14.0 | 77 | 14 | 124 |
| 14.1–16.0 | 83 | 16 | 133 |
| 16.1–18.0 | 93 | 18 | 143 |
| 18.1–20.0 | 101 | 20 | 153 |
Standard 8XD Dimensions
| Diameter (mm) | Cutting Length (mm) | Shank (mm) | Overall Length (mm) |
| 3.0–3.7 | 40 | 6 | 78 |
| 3.8–4.7 | 47 | 6 | 87 |
| 4.8–6.0 | 56 | 6 | 94 |
| 6.1–7.0 | 67 | 8 | 105 |
| 7.1–8.0 | 74 | 8 | 113 |
| 8.1–10.0 | 92 | 10 | 135 |
| 10.1–12.1 | 110 | 12 | 158 |
| 12.1–14.0 | 128 | 14 | 176 |
| 14.1–16.0 | 146 | 16 | 197 |
| 16.1–18.0 | 163 | 18 | 214 |
| 18.1–20.0 | 181 | 20 | 234 |
Applicable Materials
The GD Series is optimized for a broad range of ferrous and industrial materials, including:
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Carbon steel
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General steel
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Alloy steel
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Mold steel
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Tempered steel
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Grey cast iron
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Nodular cast iron
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Titanium alloy
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Nickel-based alloy materials
For demanding materials such as hardened mold steel, titanium alloy, or Inconel 718, cutting speed and feed should be selected according to actual machine rigidity, workpiece clamping, tool diameter, cooling method, and machining conditions.
Application Industries
Solid Carbide Standard Drill Bits GD Series are suitable for:
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Automotive component machining
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Aerospace component production
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Mold manufacturing
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Precision mechanical machining
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Hardware manufacturing
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CNC machining factories
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Automated production lines
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General metalworking
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High-speed batch drilling
Recommended Cutting Conditions
Cutting parameters should be adjusted according to the actual machine, workpiece, tool diameter, clamping rigidity, and cooling method. The following ranges can be used as starting references.
External Cooling
| Tool Diameter | Typical Vc Range (m/min) | Typical Feed Range (mm/rev) |
| ≤D6 | 10–80 | 0.03–0.27 |
| ≤D8 | 10–80 | 0.03–0.30 |
| ≤D12 | 10–105 | 0.05–0.35 |
| ≤D16 | 10–110 | 0.07–0.35 |
| ≤D20 | 10–110 | 0.07–0.35 |
For carbon and general steels, higher cutting speeds can generally be used than for hardened steel, titanium alloys, and nickel-based alloys. Parameters should be reduced when machine rigidity, workpiece stability, or chip evacuation is insufficient.
Coolant Cutting
| Tool Diameter | Typical Vc Range (m/min) | Typical Feed Range (mm/rev) |
| ≤D6 | 10–110 | 0.05–0.23 |
| ≤D8 | 10–120 | 0.05–0.30 |
| ≤D12 | 15–150 | 0.08–0.35 |
| ≤D16 | 15–150 | 0.08–0.35 |
| ≤D20 | 20–160 | 0.08–0.35 |
The recommended values are reference ranges rather than fixed parameters. Actual cutting conditions should be optimized according to workpiece hardness, machine spindle performance, tool overhang, hole depth, coolant pressure, and chip evacuation.
Why Choose GD Series Carbide Drills?
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1–20 mm comprehensive diameter range
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3XD, 5XD, and 8XD options
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Internal coolant-through design
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140° drill point geometry
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Ultra-fine grain carbide substrate
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HRC60+ substrate hardness
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TiN/TiCN/AlTiN coating options
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Self-centering drilling capability
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Reduced vibration and stable positioning
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Efficient chip evacuation
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Suitable for dry and wet cutting
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Designed for high-speed CNC machining
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Suitable for continuous and batch production
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Supports general steel, mold steel, alloy steel, cast iron, and other materials
B2B Supply & Customization
CHANGZHOU BOSTONTOOL CO.,LTD. provides factory-direct carbide cutting tool supply for distributors, machining companies, tooling suppliers, and industrial buyers.
Standard GD Series sizes from 1 mm to 20 mm are available, while customized solutions can be discussed for non-standard diameters, special flute lengths, coating requirements, drill-point configurations, and customer logo laser marking.
OEM/ODM support is available for qualified projects. Standard products can support sample orders and batch procurement, while customized orders can be scheduled according to specifications and production requirements.
Factory & Quality Advantages
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Factory Direct Supply: Independent manufacturing facilities and CNC production capabilities.
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Process Quality Control: Inspection covers carbide material, grinding, coating, finished dimensions, and product consistency.
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Standard Size Availability: Full 1–20 mm standard range supports regular purchasing requirements.
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Technical Support: Drilling parameter guidance and machining recommendations are available.
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Batch Production: Suitable for distributors, OEM customers, and automated manufacturing applications.
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Global Export Packaging: Strong packaging is used for long-distance transportation, with non-wooden packing statements or fumigation certificates available when required.
Packaging, Delivery & Trade Information
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Packing: Strong export package suitable for long-distance transportation.
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Delivery: Lead time depends on order quantity and product specifications.
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Loading Port: According to seller's arrangement.
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Inspection: In accordance with BOSTON quality standards.
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Payment: 100% T/T in advance according to contract terms.
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Insurance: Overseas insurance arranged according to agreed trade terms.
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Non-Standard Orders: Quantity tolerance and return conditions are subject to the agreed contract.
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Claims: Quality or quantity discrepancies should be reported according to the applicable contractual inspection and claim terms.
Frequently Asked Questions
Q1: What makes GD Series carbide drills different from conventional drills?
The GD Series combines an ultra-fine grain carbide substrate, 140° drill point, optimized flutes, self-centering geometry, internal coolant, and nano composite coating. This combination is designed to improve drilling stability, tool life, chip removal, and machining efficiency.
Q2: Can the GD Series be used for dry cutting?
Yes. The GD Series supports both dry and coolant-assisted wet cutting. Coating selection and cutting parameters should be matched to the workpiece material and actual machining conditions.
Q3: What hole accuracy can the drills achieve?
Under suitable machine, workpiece, and cutting conditions, the self-centering design and optimized cutting geometry can achieve hole dimensional accuracy up to m7 grade.
Q4: What materials can these carbide drills machine?
They are suitable for carbon steel, general steel, alloy steel, mold steel, tempered steel, cast iron, and other metal materials. Special attention should be given to cutting parameters when machining titanium alloys, hardened steels, or nickel-based alloys.
Q5: Are custom sizes available?
Yes. CHANGZHOU BOSTONTOOL CO.,LTD. supports customization for non-standard diameters, flute lengths, coatings, drill-point angles, and customer logo laser marking, subject to project requirements.
Q6: What is the benefit of internal coolant?
Internal coolant delivers cutting fluid closer to the cutting area, helping control cutting temperature, improve chip evacuation, and stabilize deep-hole drilling. It is particularly useful for long-cycle CNC and automated production.
Product Summary
Solid Carbide Standard Drill Bits GD Series provide a high-performance drilling solution for CNC machining applications requiring precision, rigidity, efficient chip removal, and extended tool life. With 1–20 mm diameters, 3XD/5XD/8XD flute options, internal coolant, self-centering geometry, and multiple coating choices, the series is suitable for general-purpose metal machining and high-volume production.
For standard carbide drills, bulk purchasing, OEM/ODM requirements, or application-specific drilling solutions, contact CHANGZHOU BOSTONTOOL CO.,LTD. for technical specifications and quotation.






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