DESCRIPTION
Product Overview
This industrial-grade 8.0mm solid carbide twist drill bit is engineered for high-speed, precision hole-making in demanding metalworking applications. Featuring an 8.0mm cutting diameter, 41mm flute length, 8mm straight shank, and 79mm overall length, this 3D depth-to-diameter ratio drill delivers maximum structural rigidity, rapid chip evacuation, and tight hole tolerances across ISO P (Steels), ISO M (Stainless Steels), and ISO K (Cast Iron) workpiece materials.
2. Technical Specifications
Cutting Diameter: 8.0 mm
Flute Length: 41 mm
Shank Diameter: 8.0 mm
Overall Length: 79 mm
Drilling Depth Ratio: 3D (Up to 3 times hole depth)
Substrate Material: Premium Ultra-Fine Micro-Grain Solid Carbide
Flute Design: Dual helical spiral flutes for fast chip curling and cooling
Shank Type: Cylindrical Straight Shank (DIN 6535 HA equivalent)
Machining Type: High-efficiency CNC hole drilling, blind hole, and through-hole machining.
| Cutting Diameter (D) | Flute Length (L1) | Shank Diameter (d) | Overall Length (L) | Drilling Depth Range |
| 3.0 mm | 20 mm | 3.0 mm | 54 mm | 3D (0 - 9 mm) |
| 3.5 mm | 20 mm | 4.0 mm | 54 mm | 3D (0 - 10.5 mm) |
| 4.0 mm | 24 mm | 4.0 mm | 55 mm | 3D (0 - 12 mm) |
| 4.5 mm | 24 mm | 5.0 mm | 58 mm | 3D (0 - 13.5 mm) |
| 5.0 mm | 28 mm | 5.0 mm | 62 mm | 3D (0 - 15 mm) |
| 5.5 mm | 28 mm | 6.0 mm | 66 mm | 3D (0 - 16.5 mm) |
| 6.0 mm | 28 mm | 6.0 mm | 66 mm | 3D (0 - 18 mm) |
| 6.5 mm | 34 mm | 8.0 mm | 79 mm | 3D (0 - 19.5 mm) |
| 7.0 mm | 34 mm | 8.0 mm | 79 mm | 3D (0 - 21 mm) |
| 7.5 mm | 41 mm | 8.0 mm | 79 mm | 3D (0 - 22.5 mm) |
| 8.0 mm | 41 mm | 8.0 mm | 79 mm | 3D (0 - 24 mm) |
| 8.5 mm | 47 mm | 10.0 mm | 89 mm | 3D (0 - 25.5 mm) |
| 9.0 mm | 47 mm | 10.0 mm | 89 mm | 3D (0 - 27 mm) |
| 9.5 mm | 47 mm | 10.0 mm | 89 mm | 3D (0 - 28.5 mm) |
| 10.0 mm | 47 mm | 10.0 mm | 89 mm | 3D (0 - 30 mm) |
| 10.5 mm | 55 mm | 12.0 mm | 102 mm | 3D (0 - 31.5 mm) |
| 11.0 mm | 55 mm | 12.0 mm | 102 mm | 3D (0 - 33 mm) |
| 12.0 mm | 55 mm | 12.0 mm | 102 mm | 3D (0 - 36 mm) |
| 14.0 mm | 60 mm | 14.0 mm | 107 mm | 3D (0 - 42 mm) |
| 16.0 mm | 65 mm | 16.0 mm | 115 mm | 3D (0 - 48 mm) |
| 20.0 mm | 79 mm | 20.0 mm | 131 mm | 3D (0 - 60 mm) |
Typical Applications
Automotive & Machinery Parts: Hole drilling in engine brackets, mounting plates, hydraulic manifolds, and steel housings.
Die & Mold Fabrication: Precision guide pin and ejector hole drilling in tool steels and pre-hardened mold plates.
General CNC Machining: Ideal for high-volume automated CNC vertical machining centers (VMC) and lathe drilling setups.
CNC Inserts - Frequently Asked Questions
1. How do I choose the right grade for my specific machining application?
Choosing the correct grade is crucial for tool life and performance. We provide a comprehensive Grade Cross-Reference Chart that maps our CD Carbide grades to major international brands like Sandvik, Mitsubishi, and Kyocera. If you are unsure, simply provide us with the workpiece material (P, M, K, S, H) and machining conditions, and our engineers will recommend the best solution.
2. Can you provide customized CNC tools based on our drawings?
Yes. As a factory-direct manufacturer, we specialize in bespoke engineering. Whether you need non-standard dimensions, specific chipbreakers, or customized coatings for unique alloys, our technical team can develop products based on your technical drawings (PDF/STEP) or physical samples.
3. Do you offer free samples for testing before bulk orders?
We understand that "trial cutting" is the only way to verify tool stability. We offer sample packs for professional buyers to test performance on their own CNC machines. Please contact our sales team with your machine specifications and the material you are processing to request your trial samples.
4. How do you ensure the quality consistency of your carbide inserts?
Our quality control is integrated into every step of the production process in Zhuzhou. We use high-purity tungsten carbide powder and advanced PVD/CVD coating equipment. Each batch undergoes rigorous inspection, including microscopic edge analysis and hardness testing, to ensure that the performance of the 1,000th insert is identical to the 1st.
5. What is the typical lead time for international B2B orders?
For standard models in stock (such as WNMG, CNMG, etc.), we usually ship within 3-5 business days. For customized tools or large-volume OEM orders, the production cycle typically ranges from 2 to 4 weeks, depending on the complexity of the design and coating requirements.
6. Are you a manufacturer or a trading company?
We are a direct manufacturing enterprise based in Zhuzhou, the hunan of China’s tungsten carbide industry. By cutting out the middleman, we provide factory-direct pricing and faster technical support. This allows us to offer more flexible MOQs (Minimum Order Quantities) for small-to-medium-sized distributors and specialized machine shops.
