ASTM E18-24 pdf download

ASTM E18-24 pdf download,Standard Test Methods for Rockwell Hardness of Metallic Materials.

The current suite of test methods is designed to assess the Rockwell hardness and Rockwell superficial hardness of metallic substances through the Rockwell indentation hardness technique. The standard delineates the necessary criteria for Rockwell hardness testing equipment and outlines the protocols for executing Rockwell hardness assessments.

The method encompasses details for the utilization of handheld Rockwell hardness testing devices, which employ the Rockwell hardness testing principle and are capable of satisfying all the stipulations of this method, including both direct and indirect validations of the testing equipment. Handheld Rockwell hardness testing devices that are unable to meet the direct verification criteria but can be verified through indirect means are addressed in Test Method E110.

Units of Measurement—In the original development of the Rockwell hardness test, force was measured in kilogram-force (kgf) and indentation ball diameters were measured in inches (in.). This standard adopts the units of the International System of Units (SI), specifying force in Newtons (N) and length in millimeters (mm). Yet, in recognition of historical usage and ongoing convention, force values in kgf and ball diameters in inches are provided for reference purposes, and much of the standard’s discourse employs these units.

The fundamental principles, testing protocols, and verification processes are fundamentally the same for both the Rockwell and Rockwell superficial hardness tests. The primary distinction between the two lies in the reduced testing forces employed in the Rockwell superficial test versus the Rockwell test. The same indenters, in various types and sizes, can be used for either test, contingent upon the chosen scale. Consequently, unless otherwise specified, the term “Rockwell” in this standard refers to both Rockwell and Rockwell superficial hardness tests.