Metric Coarse Spiral Flute HSS - EV. Oxidised finish. Tolerance 6H. Machine Taps Spiral Flute 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. Made from a super grade high speed steel with extra vanadium content. This has a distinct advantage with taps, by increasing wear resisting properties and extending tool life significantly. These taps are intended for general application where consistent results and improved tool life are important. Threads can be produced in a range of steels, including stainless and cast steels as well as some long chip non-ferrous materials. 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 c