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 heavy gauge metals over 1/8" thick, barstock, and angle iron. Made in the USA.