These blades feature a 1/2" shank for use in all standard reciprocating saws. They are a bi-metal construction with an alloy steel blade and 8% cobalt cutting edge that is electron beam welding to the blade. This provides a blade with triple the life of standard reciprocating saw blades. This blade is made to cut metal under 18 gauge and galvanized pipe under 18 guage, among other uses. Made in the USA.