This International Standard specifies the mechanical and performance properties for prevailing torque type steel nuts when tested at an ambient temperature range of +10 °C to +35 °C. It includes a single test to determine the prevailing torque properties (performance properties) and/or the torque/clamp force properties. This International Standard applies to prevailing torque all metal type nuts and prevailing torque non-metallic insert type nuts: a) with triangular ISO thread according to ISO 68-1; b) with diameter/pitch combination according to ISO 261 and ISO 262; c) with coarse pitch thread M3 to M39 and mechanical properties according to ISO 898-2; d) with fine pitch thread M81 to M393 and mechanical properties according to ISO 898-6; e) within the temperature range of 50 °C to +150 °C for prevailing torque all metal type nuts; NOTE 1 See Clause 7, paragraph 3 f) within the temperature range of 50 °C to +120 °C for prevailing torque non-metallic insert type nuts. NOTE 2 See Clause 7, paragraph 4.