Overview:
The KAR Industrial 540-112 is a 15mm diameter, single-flute cobalt M35 countersink with an 82° included angle — the standard angle for seating SAE flat-head screws (UNF and UNC). The single-flute geometry prevents chatter at higher spindle speeds and is particularly effective in smaller hole openings where multi-flute tools cannot track cleanly. Cobalt M35 construction provides meaningfully greater heat resistance and hardness than standard HSS, making this countersink a reliable choice for countersinking stainless steel, hardened alloys, and other difficult materials that would quickly degrade a conventional tool. The 8mm round shank fits standard drill chucks and milling machine collets.
Features:
- 82° included angle seats SAE flat-head screws (UNF/UNC) flush and clean
- Single-flute design eliminates chatter at higher RPMs and works in smaller pre-drilled holes
- Cobalt M35 steel offers superior hardness and heat resistance vs. standard HSS — ideal for stainless steel and hardened alloys
- Suitable for metal, hardwood, plywood, and plastics
- 8mm round shank for compatibility with standard drill chucks and collets
- Part of the KAR 540 single-flute metric countersink series (10mm, 15mm, 20mm, 25mm, 30mm)
Specifications:
- Body Diameter: 15mm
- Shank Diameter: 8mm
- Included Angle: 82°
- Flutes: 1
- Material: Cobalt M35
- Application: SAE flat-head screws (UNF/UNC), metal, stainless steel, hardwood, plastic
- Series: KAR 540 (1-flute metric cobalt)