Bosch 2 608 833 779 poranterä kiviporanterä 1 kpl

Bosch HSS drill bit 4 mm diameter is a high-speed steel twist bit engineered for drilling metal and other hard materials. Designed to meet Bosch quality standards, this 4 mm drill bit delivers accurate, clean holes when used with handheld drills and drill presses. Its ground point and consistent geometry ensure reliable centring and smooth penetration in sheet metal, thin plates and other compact workpieces.

Advantages

The 4 mm HSS construction offers good wear resistance and heat tolerance for prolonged cutting performance during metalworking. Precise flute geometry facilitates efficient chip evacuation and reduces clogging, while the accurately ground tip improves centring and reduces walking on the work surface. Compatible with standard drill chucks, the bit provides repeatable hole diameters and consistent finish for assembly and repair tasks.

Suitable for

• Drilling steels, stainless steel (thin sections) and non-ferrous metals
• Metal fabrication, maintenance and repair work
• Component assembly and fastening hole preparation
• Use with handheld electric drills and bench drill presses

Key specifications

• Material: high-speed steel (HSS)
• Shank type: cylindrical (suitable for standard chucks)
• Diameter: 4 mm
• Tip style: ground twist point for improved centring
• Intended materials: metal and other hard materials

How to use

Select the proper drill speed and feed for the material being drilled; lower speeds are generally recommended for harder metals. Secure the workpiece and clamp or use a vice to prevent movement. Fit the 4 mm HSS bit into the drill chuck and tighten firmly. For metal drilling, apply steady pressure and use cutting fluid or coolant where appropriate to reduce heat and extend tool life. Retract the bit periodically to clear chips when drilling deeper holes.

Recommendations

For best results when drilling metal, use appropriate cutting lubricant, start with a centre punch for precise hole placement on thin or slippery surfaces, and match drill speed to material hardness. Replace the bit if wear or chipping affects hole quality.