STRESSPROOF® is made by a patented process which consists of drawing the bar through a special die under heavy draft, then stress relieving it. This severe cold working combined with the stress relieving results in a high strength bar with good stability and exceptional machinability. STRESSPROOF® can often replace heat treated alloy steel for machined parts requiring hardness in the range 23-30 HRC. It can be induction hardened but should be watched for quench cracks because of the high sulfur and manganese content. Welding is not recommended. STRESSPROOF® exceeds ASTM A311, Class B.

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FATIGUE-PROOF® is an even higher strength grade made by various combinations of mechanical working and thermal treatments. This high strength bar can eliminate heat treating in the 32-36 HRC range plus the secondary operations associated with heat treating, i.e., cleaning, straightening, re-machining and inspection. All this, in combination with free machining, works to reduce end costs. FATIGUE-PROOF® can be induction hardened using the same precautions as with STRESSPROOF®. Welding is not recommended.