Specifies materials, properties, basic design details, accuracy and finish of vernier callipers reading to 0.1 and 0.05 mm in sizes up to 1000 mm and to 0.02 mm in sizes up to 300 mm. An appendix gives notes on the testing of the more important features of the instruments. It does not apply to dial callipers but these callipers may comply except for read-out and indicating mechanism.