CSN EN ISO 4033 This document specifies the characteristics of hexagon high nuts (style 2), in steel and stainless steel, with metric coarse pitch thread M5 to M39, and with product grades A and B. If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2. Original English text of CSN EN Standard. The price of the Standard included all amendments and correcturs.