Chord Method of Evaluating Surface Microstructural Characteristics ARP1820C

DOI: https://doi.org/10.4271/ARP1820C

Issuing Committee: AMS E Carbon and Low Alloy Steels Committee

Publisher: SAE International

Pages: 7

Rationale: ARP1820C results from a Five-Year Review and update of this specification with rewritten Introduction and Scope to add clarity, disc surface texture changed from 32 to 18 as it was more desirable but that higher texture may be needed for smaller diameters (3.1), added ASTM E385 for determining Knoop microhardness and allowed for staggered indentations (3.5), changed hardness for Depth of Decarburization to be consistent with AMS2759 (3.6), added clarifying wording for Inadvertent Carburization and Nitriding (3.7.2), and Figures 2, 3, and 4 were replaced with more accurate figures.