RUKO MGB-DIN5156-HSSCo-55°-Rp-1/8 Countersink Bit, HSSCo 5%, DIN 335 C, 90°, 3.2-12.7 mm, 8 mm Shank

Machinists and metalworkers use the RUKO MGB-DIN5156-HSSCo-55°-Rp-1/8 countersink bit to create clean, precise chamfers and deburr holes in steel, cast iron, non-ferrous metals, and plastics. Its HSSCo 5% cobalt high-speed steel construction delivers high heat resistance and long tool life, even when countersinking tough materials.

Key specifications

• Material: HSSCo 5% (High-Speed Steel Cobalt)
• Standard: DIN 335 C
• Countersink angle: 90°
• Working diameter range: 3.2 - 12.7 mm (1/8" - 1/2")
• Maximum diameter (D1): 12.7 mm (1/2")
• Shank diameter (D2): 8 mm
• Overall length (L1): 56 mm
• Number of flutes: 3
• Shank type: Cylindrical
• Coating: Uncoated
• Cutting direction: Right-hand cutting
• Manufacturing process: Ground

Why choose it

The 5% cobalt content in the HSSCo steel provides superior hardness and wear resistance compared to standard HSS, allowing for faster cutting speeds and longer intervals between regrinds. The three-flute design ensures smooth, chatter-free countersinking, while the 90° angle matches standard flat-head screws for flush seating.

Ideal use cases

• Countersinking holes for flat-head screws in metal components
• Deburring drilled holes to remove sharp edges
• Chamfering edges for aesthetic or functional purposes
• Preparing workpieces in machine shops, metal fabrication, and maintenance workshops

Good to know

This countersink bit is designed for use in stationary machines or hand drills with adequate power. The cylindrical shank fits standard drill chucks. No coating is applied, which facilitates easy resharpening when needed.