Description
Description
Bordo HSS Cobalt UNF Spiral Point Tap (3134)
HSS-Co5 (Cobalt) UNF Spiral Point (Gun Nose) machine tap.
Cobalt HSS taps are extremely hard and provide superior performance and increased tool life especially in stainless steel and high tensile steel.
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 Fine thread form was introduced in 1948 as an attempt to standardise thread forms in the USA, Canada and the UK.
The thread profile of UNF is the same as for 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).
When used on external threads this series has greater tensile stress area than coarse threads of the same size.
Fine series threads will resist stripping out better than coarse threads in areas where the external and mating internal threads are subjected to loads equal to or greater than the capacity of the screw or bolt.
Fine threads are also used where the length of engagement is limited 1-1/4 or where wall thickness demands a fine pitch.
