Dormer E037 Spiral Flute MTT-X 1/4-28 Tap

Spiral flute tap with chamfer form C with a 2-3xP plug lead, for Unified National Fine thread UNF 1/4" with 28 TPI and 3B class of fit with H3 pitch diameter limits, dimensions according to ANSI standard with 0.2550" shank and 0.1910" square drive, powder metallurgical HSS-E with bright finish and 45° helix angle for 2.5xD blind hole threading in free machining and plain carbon steel and wrought or cast aluminum