HSS Step Drill Bits
The all-in-one solution for drilling, enlarging, and deburring. Precision engineered for sheet metal, steel, and stainless steel.
Product Series
Three grades of performance for every application
Standard Duty (HSS 4241)
Cost-effective solution for general maintenance and DIY. Ideal for drilling wood, plastic, and thin aluminum sheets.
Industrial Duty (HSS M2)
Professional grade M2 (6542) steel for daily industrial use. Offers 3x longer life when drilling mild steel and iron.
Extreme Duty (M35 Cobalt)
Maximum performance with 5% Cobalt added. Specifically engineered for cutting stainless steel and hard abrasive materials.
Technical Specifications
Precision manufactured to international standards
Available Sizes & Step Configuration
Three standard configurations covering 4-32mm drilling range
| Name | Steps | StepList | Increment | Applications | IdealFor |
|---|---|---|---|---|---|
| Compact Series (4-12mm)Compact Series (3/16" - 1/2") | 9 Steps | 4mm 5mm 6mm 7mm 8mm 9mm 10mm 11mm 12mm | 1mm increment1/16" increment | Light duty, thin materials (≤2mm), electrical boxes, plastic housingsLight duty, thin materials (≤1/16"), electrical boxes, plastic housings | DIY and maintenance work |
| Standard Series (4-20mm)Standard Series (3/16" - 13/16") | 9 Steps | 4mm 6mm 8mm 10mm 12mm 14mm 16mm 18mm 20mm | 2mm increment1/16" increment | Medium duty, general metalworking (≤4mm), HVAC installations, automotive repairMedium duty, general metalworking (≤3/16"), HVAC installations, automotive repair | Most common industrial applications |
| Extended Series (4-32mm)Extended Series (3/16" - 1-1/4") | 15 Steps | 4mm 6mm 8mm 10mm 12mm 14mm 16mm 18mm 20mm 22mm 24mm 26mm 28mm 30mm 32mm | 2mm increment1/16" increment | Heavy duty, thick sheet metal (≤5mm), structural steel, industrial enclosuresHeavy duty, thick sheet metal (≤3/16"), structural steel, industrial enclosures | Professional fabrication and construction |
How to Use Step Drill Bits
Four primary applications for maximum versatility
Drilling Multiple Hole Sizes
One tool replaces an entire set of twist drills. Simply drill to the desired depth to achieve the required hole diameter. The size markings on each step ensure precise results.
Use moderate speed (500-1500 RPM) and steady pressure for best results.
Enlarging Existing Holes
Center the bit in the existing hole and drill deeper to enlarge without wandering. The self-centering split point ensures the bit stays on track even when starting in an existing hole.
The conical shape prevents grabbing and provides smooth enlargement.
Deburring & Chamfering
After drilling to your target size, lightly touch the next larger step to the hole edge. This removes burrs and creates a professional chamfered edge in one motion.
No need for separate deburring tools or files.
Drilling Curved Surfaces
Unlike twist drills, step bits excel at drilling pipes, tubes, and curved metal surfaces. The wide flute design and gradual taper prevent skating and provide stable cutting.
Especially effective for conduit, exhaust pipes, and round structural members.
Wholesale & OEM Information
Professional manufacturing services for global partners
Packaging Options
- Plastic Box Individual clear plastic boxes with product label
- Metal Case Durable metal index case, ideal for 3-5 piece sets
- Blow-molded Case Premium presentation case with foam insert
- Blister Card Retail-ready blister packaging with custom header card
- Bulk Packaging Inner boxes (50-100pcs) for large volume orders
OEM/ODM Services
- Custom size configurations & step increments
- Laser engraving of company logo on shank
- Custom surface coatings (TiN, TiAlN, TiCN)
- Branded packaging design & printing
- Private label manufacturing
Order Details
Minimum Order Quantity
1000 pieces per specification
Production & Delivery
15-25 days for standard specifications
Frequently Asked Questions
What is the difference between Straight and Spiral flutes?
Straight flutes are easier to sharpen and offer stable drilling. Spiral flutes (Double Flute) offer faster chip removal, smoother cutting, and extended tool life, making them ideal for professional use. Spiral flutes are recommended for materials that produce long, stringy chips like aluminum and mild steel.
Can your step drills cut Stainless Steel?
Yes, our Extreme Duty M35 (Cobalt) series is specifically designed for stainless steel and hardened materials. For regular steel or iron, our Industrial M2 series is the best choice. For occasional stainless work, use M2 with proper lubrication and reduced speed.
What is the maximum material thickness I can drill?
Maximum thickness depends on the material and drill grade:
- HSS 4241: Up to 2mm (soft materials like aluminum, plastic)
- HSS M2: Up to 4mm (mild steel, iron)
- M35 Cobalt: Up to 5mm (stainless steel, hardened steel)
For thicker materials, use a pilot hole or dedicated annular cutters.
What RPM should I use?
Recommended speeds vary by material and hole size:
- Aluminum/Plastic: 1500-2000 RPM
- Mild Steel: 800-1200 RPM
- Stainless Steel: 400-800 RPM (with M35 Cobalt)
Lower speeds for larger holes (>20mm). Always start slow and increase gradually. Use cutting fluid for best results.
Do I need to use cutting fluid or lubricant?
Yes, for metal drilling. Use:
- Cutting oil or tapping fluid for steel and stainless steel
- WD-40 or kerosene for aluminum
- No lubricant needed for wood or plastic
Proper lubrication extends tool life by 2-3x and produces cleaner holes.
What's the advantage of the Split Point design?
All our step drills feature a self-centering 118° or 135° Split Point, which prevents "walking" (skating) on the metal surface and eliminates the need for a center punch. The 135° point is better for harder materials, while 118° excels in softer metals and provides faster penetration.
Should I choose Hex shank, 3-Flat shank, or Round shank?
- Hex Shank (1/4"): Best for cordless drills and drill/drivers. Prevents slipping under load. Most popular for field work.
- 3-Flat Shank: For drill chucks. Provides secure grip while allowing precise centering.
- Round Shank: Compatible with all chucks but may slip under heavy load. Best for stationary drill presses.
Do you offer custom sets and packaging?
Yes, we provide:
- 3-piece sets (4-12, 4-20, 4-32mm) in Metal Boxes, Plastic Cases, or Blow-molded Cases
- 5-piece sets with additional intermediate sizes
- Custom logo laser engraving on shank
- Blister packaging for retail
- Bulk packaging for OEM
MOQ: 1000 pieces. Delivery: 15-30 days.
How do I know when the drill bit needs sharpening or replacement?
Replace or sharpen when you notice:
- Excessive heat or smoke during drilling
- Rough, torn hole edges instead of clean cuts
- Increased drilling time or pressure required
- Visible chips or cracks on cutting edges
- Blue discoloration (overheating damage)
Professional resharpening is recommended for M2 and M35 grades.
Can step drill bits be resharpened?
Yes, but resharpening requires specialized equipment to maintain the step geometry and angles. We recommend professional resharpening services for M2 and M35 grades. HSS 4241 bits are typically replaced rather than resharpened due to lower cost. Proper use and lubrication will provide 500+ holes (M35) before resharpening is needed.
Need Custom Specifications?
We offer OEM/ODM services for custom sizes, branding, and packaging.