prBAS EN ISO 10511:2026

This document specifies the characteristics of prevailing torque hexagon thin nuts (with non‑metallic insert), in steel and stainless steel, with metric coarse pitch thread M3 to M39, and with product grades A and B. NOTE            These nuts are designed with an overall height equal to mmin (as specified in ISO 898-2 and ISO 4035 for style 0) plus the prevailing torque feature. The height of the prevailing torque feature (hmax – mmin) for the non-metallic insert is identical for regular, high and thin nuts for a given diameter. Nuts with sizes D < M5 and design principles in accordance with style 0 are specified in Annex A. WARNING — Thin nuts (style 0) have a reduced loadability compared to regular or high nuts, they are not designed to provide resistance to thread stripping (see ISO 898-2). If in certain cases other specifications are requested, stainless steel grades and property classes can be selected from ISO 3506-2.