Flat cut. Carbide tipped cutting edges allow repeated resharpening. Exchangeable centre drill bit. Eject spring for the drill core for material thicknesses up to 4 mm for unalloyed steel. Stainless steel up to 2 mm. From Ø 31 mm with specially hardened mounting holder. Drill body 12 mm. Cutting depth 4 mm. Adapter shank Ø 13 mm