BS 919-3:2007

Defines requirements for the following types of gauges for checking ISO metric screw threads of nominal diameter 1 mm and larger made in accordance with BS 3643: a) Screw gauges; b) GO and NOT GO plain plug gauges and GO and NOT GO calliper and ring gauges for the crest diameters of product threads; c) Setting plugs for GO and NOT GO adjustable screw ring gauges and for GO and NOT GO screw calliper gauges; d) GO and NOT GO check plug gauges for solid type GO and GO screw ring gauges; e) NOT GO wear check plug gauges for solid type GO and NOT GO screw ring gauges.

This Part of BS 919 specifies requirements for the following types of gauges for checking ISO metric screw threads of nominal diameter 1 mm and larger made in accordance with BS 3643.

a) Screw gauges:

1. GO and NOT GO screw plug gauges;
2. GO and NOT GO screw ring gauges, solid type;
3. GO and NOT GO screw ring gauges, adjustable type;
4. GO and NOT GO screw calliper gauges, adjustable type.

b) GO and NOT GO plain plug gauges and GO and NOT GO calliper and ring gauges for the crest diameters of product threads.

c) Setting plugs for GO and NOT GO adjustable screw ring gauges and for GO and NOT GO screw calliper gauges:

1. double length;
2. single length.

d) GO and NOT GO check plug gauges for solid type GO and NOT GO screw ring gauges.

e) NOT GO wear check plug gauges for solid type GO and NOT GO screw ring gauges.

Annex A provides guidance on the functions and methods of use of the various types of gauges and Annex B recommends a procedure for the settlement of disputes arising when borderline products are inspected. Guidance on the hardness of gauges is given in Annex C, and Annex D provides information on the reference temperature.