Historical
SAE J 864-1993 (SAE J864-1993)
Surface Hardness Testing with Files
Hardness testing with files consists essentially of cutting or abrading the surface of metal parts, and approximating the hardness by the feel, or extent to which, the file bites into the surface. the term 'file hard' means that the surface hardness of the parts tested is such that a new file of proven hardness will not cut the surface of the material being tested.
CONTENT PROVIDER
Society of Automotive Engineers [sae]
Society of Automotive Engineers [sae]