Set of stepped drills for metal 4-30mm HSS-XE BLU with spiral groove, Karnasch

Cobalt step drills for metal, steel, stainless steel, acrylic glass and non-ferrous metals

Set contains drills:
1) Drill 4-12mm with strokes: 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 mm
2) Drill 4-20mm with strokes: 4 - 6 - 8 - 10 - 12 - 14 - 16 - 18 - 20 mm
3) Drill 6-30(32mm) with strokes: 6 - 8 - 10 - 12 - 14 - 16 - 18 - 20 - 22 - 24 - 26 - 28 - 30 -(32needing diameter) mm

Number of edges: 2
Clamping shank diameter: 6mm; 8mm; 10mm, with three anti-rotation faces in the chuck

Max. thickness of drilled material: 4mm
Material: HSS-XE - high-alloy cobalt high-speed HSSE steel(68 HRC)
Coating: BLUE-DUR, increases the life of the drill when drilling with very limited cooling(spray, paste), as well as for dry cutting

Cutting conditions for drill 4-12mm - steel: 1600 to 550 rpm
Cutting conditions for drill 4-12mm - stainless steel: 800 to 230 rpm
Cutting conditions for drill 4-20mm - steel: 1600 to 320 rpm
Cutting conditions for drill 4-20mm - stainless steel: 800 to 160 rpm
Cutting conditions for drill 6-30mm - steel: 1100 to 260 rpm
Cutting conditions for drill 6-30mm - stainless steel: 550 to 120 rpm

Smaller diameters can be drilled at higher speeds, with increasing drilling diameter it is necessary to reduce the cutting speed and speed. Failure to maintain the speed or overheating the drill may cause it to become dull.

Transitions to a larger diameter also perfectly needle the drilled hole.

Thanks to the spiral groove, the drilling is smooth, the chips do not stick, low cutting forces, the drilled material has fewer burrs and the tool has a longer endurance.