BS 919-4:2007

This standard BS 919-4:2007 Screw gauge limits and tolerances is classified in these ICS categories:

• 21.040.10 Metric screw threads

This British Standard specifies the limits of size for the following types of gauges, setting plugs and check plugs for the various classes of standard Unified Coarse (UNC), Unified Fine (UNF) and Unified Extra Fine (UNEF) threads specified in BS 1580-1.

1. GO and NOT GO screw gauges:
   1. screw plug gauges;
   2. solid screw ring gauges;
   3. adjustable screw ring gauges;
   4. adjustable screw calliper gauges.
2. Setting plugs for GO and NOT GO adjustable screw ring gauges and for GO and NOT GO adjustable screw calliper gauges:
   1. double length type;
   2. single length type.
3. GO and NOT GO check plugs for solid screw ring gauges.
4. GO and NOT GO plug gauges and GO and NOT GO calliper gauges for the crest diameters of product threads.

NOTE The values tabulated in this standard have been derived from the application of the tolerances specified in BS 919-1 to the limits of size given in BS 1580-1 , and reference should be made to the former standard for general information, details of the form of thread for Unified screw gauges, and tolerances on pitch and thread angle.