The standard specifies ISO metric threads with a basic profile in accordance with DS/ISO 68. The limits of the roundings in the bottom of the thread is in accordance with DS/ISO 96 5/1, where R = 0,144 P = H/6 for max. size and R min = 0,125 P = H/7 for min. size for the inner diameter d 3. The standard includes limits for coarse threads with diameter from 1 to 68 mm and with the normally used tolerance classes.