Drill bit set Topex 57H086 cobalt for metal, cylindrical shank, sizes 4, 5, 6, 8, 10 mm

Set of Topex 57H086 cobalt drill bits for metal, including five cylindrical-shank sizes: 4 mm, 5 mm, 6 mm, 8 mm and 10 mm. These drill bits are manufactured from cobalt-alloyed high-speed steel to increase heat resistance and wear life during drilling of ferrous metals and harder materials. The cylindrical shank design fits standard three-jaw chucks and hand-held drills, making the set suitable for workshop environments, metal fabrication shops and on-site maintenance.

Advantages

Cobalt alloy construction provides improved hardness and elevated temperature resistance compared with standard high-speed steel, which reduces wear and preserves cutting geometry when drilling stainless steel and other hard alloys. The included size range covers common hole diameters for mechanical assemblies and repairs, and cylindrical shanks ensure secure clamping in most drill chucks. The set offers a practical combination of sizes to reduce tool changes and to speed up typical metalworking tasks.

Suitable for

• Drilling holes in stainless steel and hardened steels
• Metal fabrication and assembly work
• Workshop repairs and maintenance tasks
• Preparing holes for fasteners in sheet metal and structural parts
• On-site service where portable drills are used

Key specifications

• Material: cobalt-alloyed high-speed steel (cobalt HSS)
• Shank type: cylindrical shank for standard drill chucks
• Included diameters: 4 mm, 5 mm, 6 mm, 8 mm, 10 mm
• Recommended use: metal drilling, including stainless and hardened alloys
• Finish: raw/ground cutting edges suitable for metalworking

How to use

Mark the drilling point and secure the workpiece to prevent movement. Select the required drill bit size from the set and mount it in a drill chuck, ensuring concentric clamping and sufficient insertion depth. Start drilling at a low speed to establish the hole, then increase speed appropriate to the material and bit size while applying steady, moderate feed pressure. Use cutting fluid or coolant when drilling stainless steel or thicker sections to reduce heat build-up and prolong bit life. Retract periodically to clear chips when drilling deep holes.

Usage recommendations

Use cutting fluid and appropriate speeds for the material being drilled, avoid excessive axial force, and inspect bit condition regularly; replace bits that show significant wear or chipping to maintain hole quality and safety.