Centre drill (combined drill and countersink) with 60° straight conical form, double ended and cylindrical body, size BS6 with 1/4" drill diameter, a body diameter of 5/8" and an overall length of 3", according to BS 328 standard to produce form A centre holes, HSS and bright finish for machining free machining, plain carbon and alloy steel and grey cast-iron
Applications:
P - Steel and cast steel(steels with alloy content ? 10% and a hardness of < 45HRC) - Primary use
M - Stainless steel(corrosion resistant steels with ? 11% chromium content) - Possible use
K - Cast Iron(castings of iron and carbon alloys with > 2% carbon content) - Primary use
N - Non-ferrous metals(metals including alloys without an appreciable amount of iron) - Possible use
S - High-temperature alloys(superalloys with high temperature stength and corrosion resistant surpassing that of stainless steel) - Possible use
For additional details please check the Manufacturer's site: