7/8" x 9 BSW Spiral Point (GUN) HSS-Co5 Tap - Goliath

About this item:

• 7/8" x 9 BSW Spiral Point (GUN) HSS-Co5 Tap - Goliath
• HSS-Co (Cobalt) Bright Finish BSW 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 Standard Whitworth angle of thread is 55 degrees as opposed to 60 degrees in Metric and Unified threads.
• This thread form was developed by Sir Joseph Whitworth in 1841.
• The thread form has rounded roots and crests and is specified in BS84:1956.
• 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.