HSS-Co8. The break-proof design of the keyhole saws makes them perfect for cutting round holes in practically all machinable materials, including cast iron, VA and tool steels, copper, bronze, aluminium and wood. All dimensions have 4/6 combination-tooth and can be used up to a cutting depth of 38 mm. The associated mounting shanks enable quick and easy clamping in hand-held and stationary drills Supplied without adapter shank