Brand: RUKO Item: Machine tap Material: 5% cobalt high-speed steel (HSSE-Co5) Application: Thread making Finish: Bright Thread Length: 0.67in Overall Length: 3.1in (79mm) For Use On: Stainless steel, brass, steel, aluminum, bronze, plastic and cast iron Thread: 1/4-28 UNF per ANSI/ASME B1.1 Tap Drill Size: #3 drill size Shank: Square shank per DIN 10, reinforced for through threads RUKO machine tap, 1/4-28 UNF, square shank per DIN 10, reinforced for through threads, 5% cobalt high-speed steel (HSSE-Co5), bright finish.