4.1 It is anticipated that the ASTM Subcommittees A01.02, A01.03, A01.06, A01.09, A01.11, A01.15, A01.19, A01.22, and A01.28 will use the standard composition limits listed in this guide for the grades identified in their product specifications unless there is a specific technical justification for doing otherwise.

4.2 The composition limits given in this guide are to be used as guides in determining limits for each of the elements included in the total composition of each grade. The composition limits have been established with the intent that each ASTM subcommittee will find it necessary to require only a minimum number of changes to reflect specific technical effects. Section 5 lists the general guidelines followed for determining the limits for each element; the limits established in this guide are based upon these guidelines.

1.1 This guide covers ASTM Subcommittees A01.02, A01.03, A01.06, A01.09, A01.11, A01.15, A01.19, A01.22, and A01.28 for specifying chemical composition limits of wrought carbon, low-alloy, and alloy steels. It is intended that these recommended grade composition limits be suitable for adoption by other standardization bodies that prepare standards for carbon, low-alloy, and alloy steel products, including discontinued steels.

1.2 Included in this guide are the recommendations for determining the number of significant figures for specifying chemical composition.

1.3 The carbon and alloy steel grades in all standards overseen by the aforementioned ASTM subcommittees have been included, except those grades applicable to restricted special end uses.

1.4 Not addressed are minor composition modifications that a specific ASTM subcommittee may find necessary to accommodate effects of normal processing or to enhance fabricability by the producer or user, or both.

1.5 Also not generally addressed (except where established by ASTM subcommittees) is a complete rationalization of all limits, especially where such would conflict with long-standing practices and is not justified by special technical effect.

1.6 This guide does not address discontinued or formerly standard steel grades. A listing of such steel grades can be found in SAE J1249. Also excluded from this guide are cast materials and welding filler metals.

1.7 In 1995, the AISI made the decision to transfer the responsibility of maintaining its numbering system to the Society of Automotive Engineers (SAE) for carbon and alloy steels (SAE J403 and SAE J404) and to ASTM International for stainless steels (Guide A959 and others). To inform users of this important event, historical information is included in the appendix of this standard.

1.8 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.