scope:

This Standard specifies steels mainly intended for machine structural use with specified harden ability bands (hereafter referred to as steel products) which are manufactured by hot rolling, hot forging and hot extruding. This Standard applies to steel products with a uniform cross-section, which are generally supplied for use after further processes of forging, cutting and heat treatment. This Standard is not applicable to steel tubes ¹⁾.

The manufacturing method and quality requirements for hot-extruded sections are given in Annex JA.

NOTE: The International Standards corresponding to this Standard and the symbol of degree of correspondence are as follows.

ISO 683-2: 2012 Heat-treatable steels, alloy steels and free-cutting steelsPart 2: Alloy steels for quenching and tempering

ISO 683-3: 2014 Heat-treatable steels, alloy steels and free-cutting steelsPart 3: Case-hardening steels (overall evaluation: MOD)

In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standard and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/lEC Guide 21-1.

Note ¹⁾ Steel tubes are covered in JIS G 3479 (Steel tubes for machine structure with specified hardenability bands).