Tools & Gear Taps & Dies HSS-Co5 Spiral Point (Gun Nose) Taps

A73FE2SP 8 x 0.43 BA Spiral Point (GUN) HSS-Co5 Tap - Goliath HSS-Co (Cobalt) Bright Finish BA Spiral Point Machine Tap. HSS-Co Spiral Point (Gun Nose) Taps. Spiral point taps, also known as "Gun nose taps", have straight flutes supplemented by angular cutting faces at the lead. The design of the cutting portion propels the swarf ahead of the tap leaving the flutes clear for the flow of coolant to the cutting teeth. Primarily designed for use in through holes, these taps can be used in blind holes provided that there is ample clearance beyond the threaded section to accommodate the swarf. The advantages of a gun nose tap are the shearing action of the angular cutting faces, which produces a fine finish on the threads and shallower flutes. This allows a stronger cross section throughout the tap. British Association thread form - in 1884 the British Association for the Advancement of Science adopted a thread form and series, primarily for use in precision equipment. It was inspired by one used in the Swiss watch and clock industry, and was formerly sometimes called the Swiss Small Screw Thread System; but is now just referred to as the BA series. Like the Whitworth thread, it has a rounded root and crest, but the included angle is 47.5°. Despite the date of origin and the British sponsorship, the BA is a metric series. Not only is it based on the metre, but the thread frequency is specified in terms of round numbers in the pitch sequence, with threads per metre allowed to fall where it may. Manufactured from HSS-Co5, this modern design tap uses straight flutes supplemented by angular cutting faces at the point to produce a fine finish on the threads. Shallower flutes achieve a stronger cross section allowing the tap to withstand greater cutting forces.