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

C220DE3SP 1 "x 14 UNS Spiral Point (GUN) HSS-Co5 Tap - Goliath HSS-Co (Cobalt) Bright Finish UNS 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. Unified National Special (UN) thread form was introduced in 1948 as an attempt to standardise thread forms in the USA, Canada and the UK. The thread profile of UNS is the same as for UN and metric threads and is described in the JIS B0206 standard. The thread is described by its major diameter and the number of threads per inch of length (TPI). UNS threads need to have the TPI specified; however the number of TPI for a specific diameter is limited. For example, within 12" diameter size, the TPI allowed are: 12" - 12 UNS, 12" - 14 UNS, 12" - 18 UNS, 12" - 24 UNS and 12" - 27 UNS. 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.