Satin chrome-plated scales and operating parts. Measuring spindle through hardened and ground. Quick drive with integral clutch. Self-centring micrometer head from 12 mm with carbide measuring jaws. From 12 mm for measuring down to the bottom of the hole. From 40 mm the micrometer head is of aluminium, to save weight.
Internal micrometers No. 428900
with appropriate setting rings.