Specifies requirements for gauge blocks of rectangular section in sizes up to 100 mm. Provision is made for five grades of accuracy, viz. calibration grade, and grades 00, 0, 1, and 2; and for five classes of calibration accuracy viz. classes 1, 2, 3, 4, and 5. Length bars of rectangular section in sizes up to 1000 mm are specified in Appendix A. Inch series gauge blocks are described in Appendix B.
