1/4"-28 UNF HSS-EV SP/FLTAP-OXIDISED

With high helix (45°), right hand spiral flutes, designed to pull swarf towards the shank of the tap. Most suitable for blind-hole tapping. Manufactured to BS 949 : Part 4 : 1990 and ISO 529 : 1975. Tolerance 2B.
Oxidised finish (black): special heat treated finish gives resistance to rust and reduces metal to metal friction. Combined with a porous surface that gives optimum lubricant retention, work-generated heat is minimised, giving prolonged cutting edge life. Use on higher carbon steels cast materials high silicon aluminiums.