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BA Thread Ring Gages

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BA Thread Ring Gages

  • British Association
  • Checks small parts under 1/4 inch
  • Manufactured to nominal class


Part# Product Name Class-of-Fit Pitch Standard Price
BATRG0 BA Go/NoGo Thread Ring 1 Normal BS 93 & BS 919 Call
BATRGDE0 BA Thread Ring Gage Set 1 Normal BS 93 & BS 919 Call
BATRG1 BA Go/NoGo Thread Ring 0.9 Normal BS 93 & BS 919 Call
BATRGDE1 BA Thread Ring Gage Set 0.9 Normal BS 93 & BS 919 Call
BATRG2 BA Go/NoGo Thread Ring 0.81 Normal BS 93 & BS 919 Call
BATRGDE2 BA Thread Ring Gage Set 0.81 Normal BS 93 & BS 919 Call
BATRG3 BA Go/NoGo Thread Ring 0.73 Normal BS 93 & BS 919 Call
BATRGDE3 BA Thread Ring Gage Set 0.73 Normal BS 93 & BS 919 Call
BATRG4 BA Go/NoGo Thread Ring 0.66 Normal BS 93 & BS 919 Call
BATRGDE4 BA Thread Ring Gage Set 0.66 Normal BS 93 & BS 919 Call
BATRG5 BA Go/NoGo Thread Ring 0.59 Normal BS 93 & BS 919 Call
BATRGDE5 BA Thread Ring Gage Set 0.59 Normal BS 93 & BS 919 Call
BATRG6 BA Go/NoGo Thread Ring 0.53 Normal BS 93 & BS 919 Call
BATRGDE6 BA Thread Ring Gage Set 0.53 Normal BS 93 & BS 919 Call
BATRG7 BA Go/NoGo Thread Ring 0.48 Normal BS 93 & BS 919 Call
BATRGDE7 BA Thread Ring Gage Set 0.48 Normal BS 93 & BS 919 Call
BATRG8 BA Go/NoGo Thread Ring 0.43 Normal BS 93 & BS 919 Call
BATRGDE8 BA Thread Ring Gage Set 0.43 Normal BS 93 & BS 919 Call
BATRG9 BA Go/NoGo Thread Ring 0.39 Normal BS 93 & BS 919 Call
BATRGDE9 BA Thread Ring Gage Set 0.39 Normal BS 93 & BS 919 Call
BATRG10 BA Go/NoGo Thread Ring 0.35 Normal BS 93 & BS 919 Call
BATRGDE10 BA Thread Ring Gage Set 0.35 Normal BS 93 & BS 919 Call


BA also is known as British Association. The British Standards Association recommends this thread form for screws smaller than ¼ inch rather than using BSW and BSF threads. This gage checks British Association external threads. BA threads are similar to Whitworth threads in terms of rounded crests and roots except that the symmetrical angles are 47 degrees and 30 minutes and the crest and root radiuses are proportionately larger. BA thread ring gages conform to S.93. Tolerances are to BS.919 Part 2 2007. BA screw thread ring gages are manufactured to nominal class. All BA thread gages are right hand only. This thread form is rarely used in the United States.
WESTport provides a complete line of BA (British Association) Thread Ring Gages. They are available in sizes from BA 0 to BA 16. Free Technical support is available from our core of engineers to assist you with any questions you may have.

WESTport Manufactured Products. 24th Anniversary Servicing Industry Worldwide (1989-2013)