ASTM A521/A521M-06(2011) - 1.4.2011
 
1. Scope

1.1 This specification covers untreated and heat-treated steel, closed-impression die forgings (Note 1) for general industrial use.

Note 1—For the definition of a forging, refer General Requirements Specification A788/A788M.

1.2 The Grades of forgings are as follows, the choice depending on design and stress or service to be imposed:

1.2.1 Grade CAUntreated, carbon steel forgings,

1.2.2 Grades CC, CC1, and CEAnnealed, normalized and tempered, carbon steel forgings,

1.2.3 Grade CFNormalized and tempered carbon steel forgings,

1.2.4 Grade CF1Double normalized and tempered carbon steel forgings,

1.2.5 Grade CGQuenched and tempered, or normalized, quenched and tempered carbon steel forgings,

1.2.6 Grade AAAnnealed, normalized, or normalized and tempered alloy steel forgings,

1.2.7 Grades AB and ACNormalized and tempered alloy steel forgings, and

1.2.8 Grades AD, AE, AF, AG, and AHNormalized, quenched, and tempered alloy steel forgings.

1.3 Unless the order specifies the applicable M specification designation, the forgings shall be furnished with the inch-pound units.

1.4 The values stated in either inch-pound units or SI (metric) units are to be regarded separately as standard. Within the text and tables, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.

 
2. Referenced Documents

E340-23

Standard Practice for Macroetching Metals and Alloys

A576-25

Standard Specification for Steel Bars, Carbon, Hot-Wrought, Special Quality

A388/A388M-26

Standard Practice for Ultrasonic Examination of Steel Forgings

A370-26

Standard Test Methods and Definitions for Mechanical Testing of Steel Products

A322-24

Standard Specification for Steel Bars, Alloy, Standard Grades

A275/A275M-23

Standard Practice for Magnetic Particle Examination of Steel Forgings

A29/A29M-23

Standard Specification for General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought

E407-23

Standard Practice for Microetching Metals and Alloys

A921/A921M-93(2022)

Standard Specification for Steel Bars, Microalloy, Hot-Wrought, Special Quality, for Subsequent Hot Forging

E381-22

Standard Method of Macroetch Testing Steel Bars, Billets, Blooms, and Forgings

E3-26

Standard Guide for Preparation of Metallographic Specimens

E45-25

Standard Test Methods for Determining the Inclusion Content of Steel

E94-04

Standard Guide for Radiographic Examination

E112-25

Standard Test Methods for Determining Average Grain Size

A788/A788M-26a

Standard Specification for Steel Forgings, General Requirements (Includes all amendments and changes 8/6/2026).