BS 869:1978

This standard BS 869:1978 Specification for toolmakers' flats and high precision surface plates is classified in these ICS categories:

• 17.040.30 Measuring instruments

This British Standard is applicable to circular hardened steel toolmakers’ flats having a maximum diameter of 200 mm, and to cast iron or granite high precision surface plates having a maximum diameter of 400 mm.

Circular hardened steel or granite toolmakers' flats up to 200 mm diameter and circular cast iron or granite high precision surface plates 250 and 400 mm diameter. Material, general design, finish, accuracy, cases, packing and marking. Composition of typical steels, cast irons and heat treatment.