Description
Overview:
The Timco 4-39 mm HSS Step Drill Bit (MPN SD439) is a precision cutter for clean, accurate holes in thin sheet metal. Made from high‐speed steel (HSS), it balances hardness and toughness for long service life. The graduated step profile lets you drill multiple hole sizes with one bit, reducing tool changes and improving efficiency. It is suitable for corded and cordless hand drills as well as drill presses and pillar drills with appropriate speed control. Designed for drilling, enlarging, and de‐burring, it performs reliably on mild steel, aluminium, brass, and other thin metals up to 4 mm (0.16 inches) thick. Ideal for trades and DIY, it supports tasks in HVAC, automotive, electrical enclosure work, and general metal fabrication.
Key Features:
- HSS construction for durability and consistent cutting performance
- 4-39 mm step range covers multiple common hole sizes in a single bit
- Clean drilling, enlarging, and de‐burring to minimise secondary finishing
- Optimised for thin sheet metals up to 4 mm (0.16 inches) thickness
- Chamfered steps help reduce snatch and produce smoother edges
- Works with hand drills and drill presses; no frequent bit changes needed
- Efficient chip evacuation for better control and reduced heat build‐up
- Recommended use with cutting fluid for longer tool life and cleaner holes
- Clear step progression improves accuracy when sizing for grommets and fittings
- Suitable for mild steel, aluminium, brass, and comparable thin metals
Typical Applications:
Creating new holes and enlarging existing holes in ducting, trunking, electrical panels, vehicle bodywork, brackets, and sheet metal fabrications. Useful for HVAC installations, automotive repairs, on‐site fitting of cable glands and grommets, and workshop prototypes where multiple diameters are required without changing bits.
Also known as:
Step bit, cone drill, unibit, stepped cone cutter, graduated drill bit, taper step drill, metal sheet step cutter.
Product Specifications
| L&S Part No. | 902 0748 |
|---|---|
| Manufacturer | Timco |
| OEM No. | SD439 |
| Unit of Sale | 1 |
| Machine Type | Handheld Construction Tools |
| Key Features | - HSS construction for durability and consistent cutting performance - 4-39 mm step range covers multiple hole sizes - Suitable for thin metals up to 4 mm thickness - Works with hand drills and drill presses - Efficient chip evacuation reduces heat build-up |
