RUKO BSB-HSSCo-4.0-20.0mm HSS-Co 5 Countersink Bit, 90°, DIN 335 C, 20mm Cutting Diameter

Countersinking, deburring, and chamfering in tough materials demand a tool that stays sharp and precise. The RUKO BSB-HSSCo-4.0-20.0mm countersink bit is made from HSS-Co 5 high-speed steel with 5% cobalt, giving it the heat resistance and edge retention needed for stainless steel, high-alloy steels, and other hard metals. Its 90° angle and three cutting edges produce clean, chatter-free countersinks in a single pass.

Who is it for

Machinists, metalworkers, and maintenance technicians who regularly work with steel, cast iron, non-ferrous metals, and plastics on drilling machines, pillar drills, or lathes. It suits both production environments and demanding workshop tasks.

Main features

• HSS-Co 5 with 5% cobalt for high wear resistance and heat tolerance
• 90° countersink angle conforming to DIN 335 C
• Three cutting edges for smooth, vibration-free countersinking
• Cylindrical shank for secure chucking in standard drill chucks
• Bright surface finish for corrosion resistance and easy chip flow

Specifications

• Material: HSS-Co 5 (5% cobalt)
• Countersink angle: 90°
• Standard: DIN 335 C
• Cutting diameter (d1): 20.0 mm
• Shank diameter (d2): 10.0 mm
• Overall length (l1): 63.0 mm
• Number of cutting edges: 3
• Shank type: Cylindrical
• Surface finish: Bright
• Application: Countersinking, deburring, chamfering
• Suitable materials: Steel, cast iron, non-ferrous metals, plastics, high-alloy steels, stainless steel, heat-resistant steels
• Recommended use: Drilling machines, pillar drills, lathes

Tips

Use a cutting oil or coolant when working with stainless or heat-resistant steels to extend tool life. For best results, run the bit at the recommended speed for the material and apply steady, even pressure to avoid chatter.