External micrometers with fixed anvils having measuring ranges of 0 to in and 0 to 13 mm, and 1 in and 25 mm up to maximum sizes of 24 in and 600 mm respectively. Includes external micrometer with interchangeable anvils for alternative measurement ranges. Material, design of frame, micrometer screw, spindle, thimble and barrel, adjustments, measuring faces, accuracy, packing and marking; setting gauges (material, general design, accuracy); test methods appended.

? British Standards Institution 2013

Amendment notes:
AMD 358 published 15 October 1969
PD 1281 published 15 October 1951
PD 4562 published 15 May 1962

BS 870:2008

AS B75-1952 - Identical