Official Answer
Answer
'Oil Tempered' SAE 1070 carbon steel is processed by heating to the austenitic range, quenching in oil, and then tempering to the desired hardness (typically HRC 45-52). This process results in a very fine tempered martensite structure, providing an excellent balance of high yield strength and toughness. For spiral retaining rings in heavy machinery, this material is preferred over 'Cold Drawn' wire because it has lower internal stresses and better dimensional stability. However, it must be protected from corrosion via phosphate coating or zinc plating. It is also critical to avoid 're-tempering' during any subsequent coating processes to maintain the structural integrity of the ring.
