Standard Test Methods for Rockwell Hardness of Metallic Materials
This standard is issued under the fixed designation E18; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A superscript epsilon (ε) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1 These test methods are under the jurisdiction of ASTM Committee E28 on Mechanical Testing and are the direct responsibility of Subcommittee E28.06 on Indentation Hardness Testing.
Current edition approved Feb. 1, 2020. Published March 2020. Originally approved in 1932. Last previous edition approved in 2019 as E18 – 19. DOI:10.1520/E0018-20
2 In this test method, the term Rockwell refers to an internationally recognized type of indentation hardness test as defined in Section 3, and not to the hardness testing equipment of a particular manufacturer.
3 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at firstname.lastname@example.org. For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website.
1.1 These test methods cover the determination of the Rockwell hardness and the Rockwell superficial hardness of metallic materials by the Rockwell indentation hardness principle. This standard provides the requirements for Rockwell hardness machines and the procedures for performing Rockwell hardness tests.
1.2 This test method includes requirements for the use of portable Rockwell hardness testing machines that measure Rockwell hardness by the Rockwell hardness test principle and
can meet all the requirements of this test method, including the direct and indirect verifications of the testing machine. Portable Rockwell hardness testing machines that cannot meet the direct verification requirements and can only be verified by indirect verification requirements are covered in Test Method E110.
1.3 This standard includes additional requirements in the following annexes:
Verification of Rockwell Hardness Testing Machines Annex A1
Rockwell Hardness Standardizing Machines Annex A2
Standardization of Rockwell Indenters Annex A3
Standardization of Rockwell Hardness Test Blocks Annex A4
Guidelines for Determining the Minimum Thickness of a Test Piece Annex A5
Hardness Value Corrections When Testing on Convex Cylindrical Surfaces Annex A6
1.4 This standard includes nonmandatory information in the following appendixes that relates to the Rockwell hardness test.
List of ASTM Standards Giving Hardness Values Corresponding to Tensile Strength Appendix X1
Examples of Procedures for Determining Rockwell Hardness Uncertainty Appendix X2
1.5 Units—At the time the Rockwell hardness test was developed, the force levels were specified in units of kilograms-force (kgf) and the indenter ball diameters were specified in units of inches (in.). This standard specifies the units of force and length in the International System of Units (SI); that is, force in Newtons (N) and length in millimeters(mm). However, because of the historical precedent and continued common usage, force values in kgf units and ball diameters in inch units are provided for information and much of the discussion in this standard refers to these units.
1.6 The test principles, testing procedures, and verification procedures are essentially identical for both the Rockwell and Rockwell superficial hardness tests. The significant differences between the two tests are that the test forces are smaller for the Rockwell superficial test than for the Rockwell test. The same type and size indenters may be used for either test, depending on the scale being employed. Accordingly, throughout this standard, the term Rockwell will imply both Rockwell and Rockwell superficial unless stated otherwise.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A623 Specification for Tin Mill Products, General Requirements
A623M Specification for Tin Mill Products, General Requirements [Metric]
A883 Test Method for Ferrimagnetic Resonance Linewidth and Gyromagnetic Ratio of Nonmetallic Magnetic Materials
A956 Test Method for Leeb Hardness Testing of Steel Products
A1038 Test Method for Portable Hardness Testing by the Ultrasonic Contact Impedance Method
B19 Specification for Cartridge Brass Sheet, Strip, Plate, Bar, and Disks
B36/B36M Specification for Brass Plate, Sheet, Strip, And Rolled Bar
B96/B96M Specification for Copper-Silicon Alloy Plate, Sheet, Strip, and Rolled Bar for General Purposes and Pressure Vessels
B103/B103M Specification for Phosphor Bronze Plate, Sheet, Strip, and Rolled Bar
B121/B121M Specification for Leaded Brass Plate, Sheet, Strip, and Rolled Bar
B122/B122M Specification for Copper-Nickel-Tin Alloy, Copper-Nickel-Zinc Alloy (Nickel Silver), and Copper-Nickel Alloy Plate, Sheet, Strip, and Rolled Bar
B130 Specification for Commercial Bronze Strip for Bullet Jackets
B134/B134M Specification for Brass Wire
B152/B152M Specification for Copper Sheet, Strip, Plate, and Rolled Bar
B370 Specification for Copper Sheet and Strip for Building Construction
B647 Test Method for Indentation Hardness of Aluminum Alloys by Means of a Webster Hardness Gage
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E74 Practices for Calibration and Verification for Force-Measuring Instruments
E92 Test Methods for Vickers Hardness and Knoop Hardness of Metallic Materials
E110 Test Method for Rockwell and Brinell Hardness of Metallic Materials by Portable Hardness Testers
E140 Hardness Conversion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hardness, Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb Hardness
E384 Test Method for Microindentation Hardness of Materials
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
2.2 American Bearings Manufacturer Association Standard:
ABMA 10-1989 Metal Balls
2.3 ISO Standards:
ISO 6508-1 Metallic Materials—Rockwell Hardness Test—Part 1: Test Method (scales A, B, C, D, E, F, G, H, K, N,T)