5/8" x 18 UNF Chrome Tap Set

UNF | UNIFIED NATIONAL FINE TAP SET

About this item:

• 5/8" x 18 UNF Chrome Tap Set
  
• Chrome Alloy UNF Hand Tap Set.
• Used as thread chasers to clean an existing thread.
• They can also be used to create a new female thread in non-ferrous metals and plastics.
• Chrome alloy taps are not suitable for creating precision, safety or critical threads.
• 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.
• 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.
• 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 are typically preceded by the use of a Taper or Intermediate Tap.