Product Name: Tin-Coated HSS Step Drill Bit
Material: HSS / Cobalt M35 High Speed Steel
Surface Finish: Tin Coated (Gold Color)
Flute Type: Spiral Flute / Straight Flute (Optional)
Application: Steel, Brass, Copper, Aluminum, Wood and Plastic
Product Overview
Our tin-coated HSS step drill bits are precision-engineered cone-shaped drill tools designed to drill multiple hole diameters with a single bit. Each step corresponds to a specific diameter, allowing you to switch between sizes instantly without changing bits — ideal for electricians, plumbers, HVAC technicians, metal fabricators and DIY users who need versatility on the job.
Made from high-speed steel (HSS) or premium Cobalt M35, the drill body is heat-treated to deliver long-lasting cutting performance. The tin (titanium nitride) coating reduces friction, dissipates heat faster, and extends tool life compared to uncoated bits.
Available Size Range
We offer a wide selection of metric step drill bits to cover different drilling needs:
| Metric Size Step Drill Bit |
| Drilling Range(mm) | Number of Steps | Dla of Steps(mm) | Overall Length(mm) | Shank Dia(mm) |
| 3-12 | 5 | 3-6-8-10-12 | / | 6 |
| 3-12 | 10 | 3-4-5-6-7-8-9-10-11-12 | / | 6 |
| 3-14 | 12 | 3-4-5-6-7-8-9-10-11-12-13-14 | / | 6 |
| 3-14 | 1 | 3-14 | / | 6 |
| 4-12 | 5 | 4-6-8-10-12 | 65 | 6 |
| 4-12 | 9 | 4-5-6-7-8-9-10-11-12 | 65 | 6 |
| 4-20 | 9 | 4-6-8-10-12-14-16-18-20 | 75 | 8 |
| 4-22 | 10 | 4-6-8-10-12-14-16-18-20-22 | 80 | 10 |
| 4-30 | 14 | 4-6-8-10-12-14-16-18-20-22-2-26-28-30 | 100 | 10 |
| 4-39 | 13 | 4-6-12-15-18-21-24-27-30-33-36-39 | 107 | 10 |
| 5-13 | 5 | 5-7-9-11-13 | 65 | 6.35 |
| 5-20 | 1 | 5-20 | / | / |
| 5-25 | 11 | 5-7-9-11-13-15-17-19-21-23-25 | / | / |
| 5-25 | 11 | 5-7-9-11-13-15-17-19-21-23-25 | 82 | 9.5 |
| 5-35 | 13 | 5-13-15-17-19-21-23-25-27-29-31-33-35 | 82 | 12.7 |
| 6-18 | 7 | 6-8-10-12-14-16-18 | / | 10 |
| 6-20 | 8 | 6-8-10-12-14-16-18-20 | 71 | 9 |
| 6-25 | 7 | 6-9-12-16-20-22.5-25 | 65 | 10 |
| 6-30 | 13 | 6-8-10-12-14-16-18-20-22-24-26-28-30 | 100 | 10 |
| 6-32 | 9 | 6-9-12-16-20-22.5-25-28.5-32 | 76 | 10 |
| 6-35 | 13 | 6-8-10-13-16-18-20-22-25-28-30-32-35 | / | 10 |
| 6-36 | 11 | 6-9-12-15-18-21-24-27-30-33-36 | 85 | 10 |
| 6-38 | 12 | 6-9-13-16-19-21-23-26-29-32-35-38 | 100 | 10 |
| 6-40 | 16 | 6-11-17-23-29-30-31-32-33-34-35-36-37-38-
39-40 | 105 | 13 |
| 8-20 | 7 | 8-10-12-14-16-18-20 | / | / |
Key Features
1. HSS / Cobalt M35 Material OptionsChoose from standard HSS for general-purpose drilling, or upgrade to Cobalt M35 for stainless steel and harder materials. Cobalt M35 retains hardness at high temperatures, making it ideal for demanding industrial applications.
2. Tin Coated SurfaceThe gold-colored titanium nitride (TiN / tin) coating reduces cutting friction by up to 40%, dissipates heat rapidly, and prevents material from sticking to the flutes. This translates to cleaner holes, faster drilling, and significantly longer bit life.
3. Spiral Flute Design (Available)Spiral flutes provide smooth chip evacuation and reduced walking on entry. For cleaner holes in thin sheet metal, the spiral flute design outperforms straight flute variants. (Straight flute also available upon request.)
4. Laser-Etched Size MarkingsEvery step diameter is permanently laser-etched onto the bit body — no printing to wear off. Read the current size at a glance without stopping to measure.
5. Multi-Size in One ToolOne step drill replaces an entire set of regular drill bits. Quickly switch between hole sizes mid-project — no need to stop and change bits.
Applications
Suitable for drilling clean, round holes in:
Metal: Steel sheet, brass, copper, aluminum
Wood: Plywood, MDF, solid wood
Plastic: PVC, acrylic, fiberglass, composite panels
Common uses:Electrical conduit openings, pipe holes for plumbing, HVAC ductwork, sheet metal fabrication, automotive repair, furniture making, curtain wall installation, and general DIY projects.
Technical Specifications
表格
| Item | Detail |
|---|
| Material | HSS / Cobalt M35 |
| Surface Finish | Tin Coated (TiN) |
| Flute Type | Spiral Flute (Straight Flute optional) |
| Shank Type | Round shank (6mm / 8mm / 10mm / 13mm options) |
| Size Range | 3–12mm up to 6–40mm (20+ sizes available) |
| Step Count | 5–16 steps per bit |
| Color | Gold |
| Customization | OEM / ODM welcome |
Packaging
Available as individual bits or as a set (e.g., 3-piece set: 4–12mm + 4–20mm + 4–32mm). Custom packaging options available upon request.
English
