Hole saw d.28mm cutting d.20mm carbide tipped w.drill and springspring PROMAT : multi-range design - carbide-tipped cutting edges allow repeated regrinding - replaceable centre drill - ejector spring for the drill core - for unalloyed steels and stainless steel for sawing flat material - pipe material - curved surfaces - overlapping holes are possible - drill body 30 mm - cutting depth 20 mm, with hand drills up to 6 mm - Application note: Use high-quality cutting oil when sawing metals, do not use cutting oil when sawing cast iron and add petroleum when sawing aluminium Further technical information: - Design: with drill bit and spring.