Tools & Gear Taps & Dies HSS Hand and Machine Taps

3038-5/16B 5/16" x 32 UNEF Bottoming HSS Tap HSS UNEF Bottoming Hand and Machine Tap. Unified National Extra Fine is a subset of UNF in which the thread forms feature a greater number of TPI than the standard UNF series. The thread profile of UNEF 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. Bottoming Taps have a lead of two threads and are used to ensure minimum thread run-out when tapping to the bottom of a blind hole. Manufactured from HSS this general purpose tap is designed for use in medium tensile materials and is for hand or general machine use.