In Reply to Parent Post by lawright
AMS 2658 Table 1 Note 3 states that the HR15T values are for parts up to .032 in nominal thickness.
Does this mean that you should not use the Rockwell 15T scale for thicknesses higher than .032 or should we use the ASTM E140 conversion tables to determine the Rockwell 15T scale hardness value for example 6061 T4 .063 thick
15T is only applicable to material gauges less than 0.032". The 15kg load and ball size is not suitable for higher thicknesses and will not return meaningful results.
If you need to test 6061 T4 for thicknesses over 0.032", you can use the E-60 minimum.