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.