ISO/NP 898-12

Fasteners — Mechanical properties of fasteners made of non-alloy and low-alloy steel — Part 12: Nuts with nominal diameters 39 mm < D  100 mm and specified property classes

Scope

This document specifies the mechanical and physical properties, for nuts with nominal diameters above 39 mm and up to 100 mm, made of non-alloy and low-alloy steel. 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.

This document applies to nuts:
— with ISO metric thread in accordance with ISO 68-1,
— with diameter/pitch combinations in accordance with ISO 262,
— with coarse pitch thread M42 to M68, and fine pitch thread M42×3 to M100×6,
— with specified property classes 8, 10 and 12 (including proof load),
— with thread tolerances in accordance with ISO 965 -1, -2 or -5,
— of two different nut styles: regular nuts (style 1) and high nuts (style 2), see Clause 5.1,
— with a minimum outside diameter or width across flats smin ≥ 1,45D,
and
— designed to mate with bolts, screws and studs with property classes in accordance with ISO 898-11 (see Annex A).

This document is not applicable for stainless steel nuts.
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 for test method),
— torque/clamp force properties (see ISO 16047 for test method),
— corrosion resistance (see e.g. ISO 4042, ISO 10683 or ISO 10684),
— fatigue resistance, or
— weldability.