Straight flute step drill
The DT16C series of internally cooled, three-step carbide drill bits are high-performance tools developed by JIAYI Tools specifically for machining complex stepped holes with multiple diameters. Their innovative "internal coolant channel + integrated three-step cutting edge" design, Precision machining of three different hole diameters can be completed in a single pass, while the internal cooling system reaches each cutting zone directly, completely resolving the pain points of traditional multi-step drilling—namely, "cumbersome processes, poor coaxiality, and insufficient heat dissipation"— It provides disruptive solutions for multi-stage stepped hole machining in the automotive, mold, and aerospace industries, among others.
| Part Number | DT16C082X |
|---|---|
| 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 features two built-in high-precision internal coolant channels capable of delivering cooling pressure up to 100 bar. The coolant reaches the third-stage cutting edge directly, improving heat dissipation efficiency by 55% and completely eliminating the risk of drill burnout during the machining of multi-step holes.
The cutting edges of each stage are designed with helix angles of 38°, 35°, and 32°, respectively, allowing chips to be discharged in an orderly, layered manner. This improves chip evacuation efficiency by 45% and prevents chip buildup and scratches on the bore wall.
The three cutting edges are machined as a single unit using a five-axis grinding machine, with a coaxiality error of ≤0.002 mm, ensuring the perpendicularity and positional accuracy of multi-step holes.
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.
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.