Tools & Gear Taps & Dies HSS Hand and Machine Taps

Pipe Taps Pipe Taps are supplied with PARALLEL threads or TAPER threads. They are much shorter than a similar size of regular hand tap - but the design features are the same. Goliath HSS taps provide a high hardness to toughness ratio - compressive and tensile strength - good abrasion resistance and resistance to micro-chipping - ensuring a long tool life. Tapered Pipe Taps are used for tapered threading by hand or machine. NPT NATIONAL PIPE TAPERED NPT is a US standard for tapered threads used to join pipes and fittings. ANSI/ASME standard B1.20.1 covers threads of 60 deg; form with flat crests and roots. The taper on NPT threads allows them to form a seal when torqued as the flanks of the threads compress against each other. However a clearance remains between the crests and roots of the threads - resulting in a leakage around this spiral. This means that NPT fittings must be made leak free with the aid of thread seal tape or a thread sealant compound. For each 12 increase in distance from the end - the diameter increases by 3/4. TAPER TAPS have a lead of eight threads and are used as a starting tap in difficult or high precision holes. INTERMEDIATE TAPS have a lead of four threads and are used in most general purpose applications to cut a thread true to a pre-drilled pilot hole. 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. Bottoming Taps are typically preceded by the use of a Taper or Intermediate Tap. Manufactured from HSS this general purpose tap is designed for use in medium tensile materials and is for hand or general machine use.