摘要 |
A drilling and tapping screw constructed from a 300 series stainless steel material which has the corrosive resistance of the high chromium high nickel content stainless steel while still being capable of drilling through carbon steel materials or the like. The product is constructed by forging the point at very slow forging speeds, resulting in a drill screw which is a predominantly martensitic structure at the drill point while predominantly austenitic in the shank and head regions. |