This standard is issued under the fixed designation E92; the number immediately 1 These test methods are under the jurisdiction of ASTM Committee E28 on. Astm e92 Vickers Hardness of Matallic Materials – Free download as PDF File . pdf), Text File .txt) or read online for free. priate safety and health practices and determine the applica- bility of regulatory limitations prior to use. 2. Referenced Documents 2. 1 ASTM Standards.
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This rise in hardness number with lower test forces is often more significant when testing higher hardness materials, and is increasingly more significant when using test forces below 50 gf see Test Method E Link to Active This link will always route to the current Active version of the standard.
Vickers and Knoop Hardness Standardizing Machines. However, in practice, the most commonly used force units are kilogram-force r92 and gram-force gf.
ASTM E92 – VICKERS HARDNESS
Standardization of Vickers and Knoop Indenters. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
When Newton units of force are used, the force must axtm divided by the conversion factor 9.
Today, the hardness numbers are internationally defined in terms of SI units, asmt is, the test force in Newtons N. Historical Version s – view previous versions of standard. Hardness, although empirical in nature, can be correlated to tensile strength for many metals, and is an indicator of wear resistance and ductility.
ASTM E92 – 17 Standard Test Methods for Vickers Hardness and Knoop Hardness of Metallic Materials
Recommendations for microindentation testing can be found in Test Method E 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.
However, because of the historical precedent and continued common usage, force values in gf and kgf units are provided for information and much of the discussion in this standard as well as the method of reporting the test results refers to these units.
Microindentation hardness tests also allow specific phases or constituents and regions or gradients too small for macroindentation e992 testing to be evaluated. The Vickers and Knoop hardness numbers were originally defined in terms of the test force in kilogram-force kgf and the surface area or projected area in millimetres squared mm 2. Asttm standard provides the requirements for Vickers and Knoop hardness machines and the procedures for performing Vickers and Knoop hardness tests.
The significant differences between the two tests are the geometries of the respective indenters, the method of calculation of the hardness 9e2, and that Vickers hardness may be used at higher force levels than Knoop hardness.
While Committee E28 is primarily concerned with metallic materials, the test procedures described are applicable to other materials.
Other materials may require special considerations, ast example see C and C for ceramic testing. For isotropic materials, the two diagonals of a Vickers indentation are equal in length. Hence, the Knoop hardness test is very useful for evaluating hardness gradients since Knoop indentations can be made closer together than Vickers indentations by orienting the Knoop indentations with the short diagonals in the direction of the hardness gradient.