The project
The customer forged the parts themselves at another facility and needed a heat-treatment provider that could hit a specific hardness and impact-toughness combination on 4340, a grade where the final quenching and tempering step is what actually develops the high-strength properties the alloy is chosen for — an as-forged 4340 part is considerably softer than its quenched-and-tempered specification. Test coupons were forged and heat-treated alongside the production batch specifically so destructive tensile and impact testing could confirm the target properties without sacrificing any of the six customer-supplied parts themselves.
Furnace charts and coupon test results were provided with the finished batch for the customer’s own quality record, alongside individual part hardness-test results confirming the batch met the specified range.