Armeg Halls 16mm,20mm,25mm,32mm Conduit Trunking Step Metal Drill Bit, ESD16-32
Precision ground, tapered cutting edges allow material up to 6mm to be drilled, burr free! 16.5mm, Clearance size for 16mm Conduit. 20.5mm, Clearance size for 20mm Conduit. 25.5mm, Clearance size for M25 Conduit.