Hole saw D.33mm Cut-T.4mm carbide tipped w.drill and springspring PROMAT : flat cut - carbide-tipped cutting edges allow repeated regrinding - replaceable centre drill - ejector spring for the drill core for material thicknesses up to 4 mm for unalloyed steels - stainless steel up to 2 mm - from 31 mm dia.thicknesses up to 4 mm for unalloyed steels - stainless steel up to 2 mm - from 31 mm Ø with specially hardened holder - drill body 12 mm - cutting depth 4 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.