Drill bit Irwin 10502535 HSS Cobalt 8.5 mm

Irwin 10502535 HSS Cobalt 8.5 mm is a high-speed steel drill bit alloyed with cobalt, engineered to drill metal and other hard materials. With an 8.5 mm cutting diameter and a ground tip geometry, this drill bit is intended for use in handheld and bench drills where increased heat resistance and edge retention are required. Construction from HSS with added cobalt improves wear performance and thermal stability compared with standard HSS bits, making it suitable for stainless steel, cast iron and other tough alloys encountered in professional and DIY metalworking.

Advantages

The cobalt-enhanced HSS composition provides greater hardness at elevated temperatures, reducing premature dulling when drilling hard materials. The precision-ground flute and tip deliver accurate centring and consistent chip evacuation, which helps maintain cutting efficiency and prolong tool life. The bit’s robust build tolerates intermittent heavy-duty use and repeated re-sharpening when necessary.

Suitable for

• Drilling stainless steel and heat-treated steels
• Punching holes in cast iron and steel alloys
• Metal fabrication, maintenance and repair tasks
• Workshop and on-site drilling with handheld or bench drills
• DIY metalworking projects requiring durable drill tips

Key specifications

• Material: high-speed steel with cobalt alloy
• Cutting diameter: 8.5 mm
• Tip style: precision ground for improved centring
• Application: metal and hard materials including stainless steel and cast iron
• Compatible drills: handheld and bench drills with appropriate chuck capacity

How to use

Secure the drill bit firmly in a compatible chuck and set the drill to an appropriate speed for the material being worked; lower speeds are recommended for stainless and hardened steels to minimise heat build-up. Use cutting fluid or coolant when drilling thicker sections to improve chip evacuation and extend tool life. Apply steady, even pressure without forcing the bit; allow the bit to cut and withdraw periodically to clear chips when drilling deep holes.

Usage recommendations

For best results, match drill speed and feed to the workpiece material, use cutting lubricant for stainless and other heat-sensitive alloys, and ensure the drill is held perpendicular to the work surface to reduce side loading. Inspect the cutting edge regularly and re-sharpen or replace the bit when wear affects performance.