Tools & Gear Taps & Dies Chrome Alloy Taps

• 7/8" x 9 BSW Bottoming Chrome Tap
• Chrome Alloy BSW Bottoming Hand Tap.
• 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.
• British Standard Whitworth has a thread angle of 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.
• The major diameter of external thread and pitch are specified by a simple numerical value (most commonly measured in millimetres).
• 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.