blue nano coated cone step drill bit clamped in cordless screwdriver on gray blur background

background bit black blue blur carpentry civil clamped closeup coated coating cone conical construction copy cordless countersink countersunk cutting different diy drill drilling edge electric engineering equipment finishing fluted gray green groove gun hard hole hss industry machine mechanical metal nano nobody occupation power precision product production profile quality repair rotate screw screwdriver service shape sharp shiny size space spiral stairstep steel step surface technology titanium tool trade turning twisted wood woodwork work working