Active Standard ASTM E18 | Developed by Subcommittee: E28.06
Book of Standards Volume: 03.01
Historical (view previous versions of standard)
Significance and Use
4.1 The Rockwell hardness test is an empirical indentation hardness test that can provide useful information about metallic materials. This information may correlate to tensile strength, wear resistance, ductility, and other physical characteristics of metallic materials, and may be useful in quality control and selection of materials.
4.2 Rockwell hardness tests are considered satisfactory for acceptance testing of commercial shipments, and have been used extensively in industry for this purpose.
4.3 Rockwell hardness testing at a specific location on a part may not represent the physical characteristics of the whole part or end product.
4.4 Adherence to this standard test method provides traceability to national Rockwell hardness standards except as stated otherwise.
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 standard includes additional requirements in annexes:
Verification of Rockwell Hardness Testing Machines
Rockwell Hardness Standardizing Machines
Standardization of Rockwell Indenters
Standardization of Rockwell Hardness Test Blocks
Guidelines for Determining the Minimum Thickness of a
Hardness Value Corrections When Testing on Convex
1.3 This standard includes nonmandatory information in appendixes which relates to the Rockwell hardness test.
List of ASTM Standards Giving Hardness Values Corresponding
Examples of Procedures for Determining Rockwell
1.4 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.
1.5 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.
1.6 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 and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
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]
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
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E92 Test Method for Vickers Hardness of Metallic Materials
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 Knoop and Vickers Hardness of Materials
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
American Bearings Manufacturer Association StandardABMA10-1989 Metal Balls Available from American Bearing Manufacturers Association (ABMA), 2025 M Street, NW, Suite 800, Washington, DC 20036.
ISO StandardsISO6508-1 Metallic Materials--Rockwell Hardness Test--Part 1: Test Method (scales A, B, C, D, E, F, G, H, K, N, T) Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org. ISO/IEC17011 Conformity Assessment--General Requirements for Accreditation Bodies Accrediting Conformity Assessment Bodies ISO/IEC17025 General Requirements for the Competence of Testing and Calibration Laboratories
Society of Automotive Engineers (SAE) StandardSAEJ417 Hardness Tests and Hardness Number Conversions Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http://www.sae.org.
ICS Number Code 77.040.10 (Mechanical testing of metals)
UNSPSC Code 41114611(Hardness testers)