scope:

This Standard specifies the low-alloyed steels for machine structural use (hereafter referred to as "steels"), which are manufactured by hot forming such as hot rolling and hot forging. Steels are normally used after further forming such as forging and cutting and heat treatment or nitriding.

NOTE 1 Depending on the thickness, steel plates and strip may include those subjected to cold rolling in addition to those manufactured by hot forming.

NOTE 2 The International Standards corresponding to this Standard are as follows.

ISO 683-1 : 1973 Heat-treatable steels, alloy steels and free-cutting steels-Part 1: Direct-hardening unalloyed and low-alloyed wrought steel in form of different black products

ISO 683-10 : 1973 Heat-treatable steels, alloy steels and free-cutting steels-Part 10: Wrought nitriding steels

ISO 683-11 : 1987 Heat-treatable steels, alloy steels and free-cutting steels-Part 11: Wrought case-hardening steels (Overall evaluation : MOD) In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standards and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/IEC Guide 21