33001/4X20H4NO3 1310180 UNC Roll Form Tap 1/4 inch x 20

Thread forming tap with lube grooves NO3 with a 2-3xP semi-bottoming lead, for Unified National Coarse thread UNC 1/4" with 20 TPI and H4 pitch diameter limits, dimensions according to ANSI standard with 0.2550" shank and 0.1910" square drive, HSS with bright finish for 3xD through or blind hole threading in free machining, plain carbon and alloy steel and wrought or cast aluminium and copper or copper alloys.