Rockwell vs. Tensile Strength

We get asked a lot what is the Rockwell for our wire. Material specifications only callout Tensile Strength not Rockwell. Fortunately there are tables that convert the Tensile Strength to Rockwell like the table shown.

As an example, .250” Music Wire; the specification for Music Wire is ASTM A228. When you look up this diameter in this specification, the tensile strength should be 230 – 255 ksi. When you look at this tensile strength in the Hardness Conversion Chart, then Rockwell C ~ 47.5 – 51.7.

Tensile Strength vs Rockwell Testing

Hardness Conversion Chart