Carbide step drill
The DT17C series of internally cooled, two-stage carbide drill bits are high-performance tools developed by JIAYI Tools specifically for machining double-diameter stepped holes. Their innovative "internal coolant channel + integrated stepped cutting edge" design, Precision machining of two holes with different diameters can be completed in a single pass, while the internal cooling system delivers coolant directly to the cutting zone, completely resolving the pain points of traditional step drilling—namely, "low efficiency, poor coaxiality, and insufficient heat dissipation"— It provides a revolutionary step-hole machining solution for the automotive, mold, and electronics industries, among others.
| Part Number | DT17C082X |
|---|---|
| Drill Bit Base Material | Ultrafine-Grained Tungsten Carbide Alloy |
| Product Name | Internally Cooled Carbide Drill Bits/Step Drill Bits |
| OEM / ODM | Made to your samples or drawings |
| Specifications | Ø11.80 × 96L × Ø12.0 × 162L |
| Lead time | 2 weeks |
| Packaging (mm) | 15 × 15 × 200mm |
| Blade Diameter DC | Ø11.8mm |
| Blade Length LCF | 96.0mm |
| Shank Diameter DC | Ø12.0mm |
| Overall length OAL | 162.0mm |
| Materials | VHM (ultrafine-grained tungsten carbide alloy) |
| Coating | AlTiN |
| MOQ | 2 pcs |
| Origin | Shenzhen, China |
Design details engineered for accuracy, tool life and process stability.
The cutter body is machined from a single piece of ultra-fine-grain carbide (HRC 68) with no welded joints. It remains stable and free of runout during high-speed, high-feed machining, with a repeatability of ≤0.003 mm.
The drill bit features two built-in high-precision internal coolant channels capable of delivering cooling pressure up to 100 bar. The coolant reaches the double-step cutting edge directly, improving heat dissipation efficiency by 50% and completely eliminating the risk of drill bit burnout during stepped hole machining.
Utilizing PVD nano-coating technology, the coating has a thickness of 2 μm, a hardness of HV3800, and a coefficient of friction as low as 0.3, resulting in a tool life that is twice as long as that of traditional coatings.
The large and small cutting edges feature 38° and 35° helix angles, respectively, allowing chips to be discharged in layers. This improves chip evacuation efficiency by 40% and prevents chip buildup and scratches on the bore wall.
The drill bit features a 140° centered design with a centering accuracy of ≤0.003 mm, allowing for direct machining without the need to pre-drill a center hole, thereby reducing the number of processing steps and improving efficiency.
Each drill bit passes a G2.5-grade dynamic balancing test, ensuring vibration-free operation at high speeds of 20,000 rpm and guaranteeing machining stability.
The cutting edge is ground using a five-axis CNC grinding machine, with a runout error of ≤0.002 mm, ensuring the roundness and cylindricity of the bore.
Pre- and post-polishing processes reduce friction and ensure excellent chip management
Starting values. Our engineers can tune parameters to your machine and workpiece.
| Workpiece material | Cutting speed vc (m/min) | Feed f (mm/rev) | Coolant |
|---|---|---|---|
| Aluminum Alloy | 80–120 | 0.1–0.25 | Internal + MQL |
| Stainless Steel | 40–70 | 0.06–0.15 | Internal + MQL |
| Steel | 50–80 | 0.08–0.2 | Emulsion |
Typical industries and parts machined with this tool.
Send your hole diameter, depth and workpiece material. We supply standard drills and custom step and special drills made to your samples or drawings.