External micrometers with fixed anvils having measuring ranges of 0 to $9H 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.
BS 870:1950 history
2011BS EN ISO 3611:2010 Geometrical product specifications (GPS). Dimensional measuring equipment. Micrometers for external measurements. Design and metrological characteristics
2008BS 870:2008 Specification for external micrometers
1950BS 870:1950 Specification for external micrometers