With all of the talk lately in heat treating chromoly parts for the Rock Bug, we thought it helpful to post a hardness conversion chart detailing the relationship between hardness and tensile strength.  A few things to remember before using this guide in your next engineering project.  Tensile values provided in this chart are given as the materials tensile “yield” strength.  Because the relationship between hardness and tensile strength is inexact, actual yield strength may vary depending on the material’s properties.  Special thanks to Instron, the recognized worldwide market leader in the materials testing industry, for providing this chart to us.