prEN ISO 898-2

This document specifies the mechanical and physical properties of nuts made of non-alloy steel or alloy steel, for three different nut styles in accordance with 5.1: — regular nuts (style 1), — high nuts (style 2), — thin nuts (style 0), in combination with: — coarse pitch thread M5 ≤ D ≤ M39, and fine pitch thread 8 mm ≤ D ≤ 39 mm, — specified property classes 04, 05, 5, 6, 8, 10 and 12 including proof loads, and able to be mated with bolts, screws and studs with property classes in accordance with ISO 898-1. These combinations are based on bolt/nut compatibility, manufacturing processes and market needs. If other combinations are needed, e.g. for nuts designed for particular applications, see ISO/TR 16224. Nuts conforming to the requirements of this document are tested at the ambient temperature range of 10 °C to 35 °C. It is possible that they do not retain the specified mechanical and physical properties at elevated and/or lower temperatures. NOTE 1 Nuts conforming to the requirements of this document are used in applications ranging from –50 °C to +150 °C, however these nuts are also used outside this range and up to +300 °C for specific applications. It is the responsibility of the user to determine the appropriate choice, and consulting an experienced fastener materials expert is recommended outside the range of –50 °C to +150 °C (several factors need to be taken into account, e.g. steel composition, duration of exposure at elevated or low temperature, the effect of the temperature on the fastener mechanical properties and clamped parts). NOTE 2 Information for the selection and application of steels for use at lower and elevated temperatures is given for instance in EN 10269, ASTM A320/A320M and ASTM A194/A194M. This document applies to the nuts specified above, with: — triangular ISO metric thread in accordance with ISO 68-1, — diameter/pitch combinations in accordance with ISO 261 and ISO 262, — thread tolerances in accordance with ISO 965-1, ISO 965-2 or ISO 965-5, and — minimum outside diameter or width across flats s ≥ 1,45D (see Annex B). For hot dip galvanized nuts, additional requirements are specified in ISO 10684. This document does not specify requirements for functional properties such as: — prevailing torque properties (see ISO 2320), — torque/clamp force properties (see ISO 16047 for test method), — weldability, or — corrosion resistance