For shops looking for a viable and cost-effective alternative to grinding without sacrificing efficiency or quality, hard turning is worth consideration. Within its application range, it can help shops move toward the goal of streamlining manufacturing by eliminating or consolidating manufacturing steps.
Hard turning can produce machining results similar to grinding without the need to invest in capital equipment and the skills associated with the grinding process. It also offers speeds significantly faster than grinding: Precision specs can be machined at production rates that are 4 to 6 times faster than comparable grinding processes.
Hard turning is applied to workpieces that are 45 Rc and higher, although hard turned work is typically found in the 58 and 68 Rc range. Parts with a low length-to-diameter ratio are the best candidates for hard turning, as well as parts made from materials such as tool, bearing, stainless and case-hardened steels and Inconel, Hastelloy, Stellite and other exotic metals.
Not only does hard turning eliminate or reduce grinding operations from the production process, but it also reduces operational steps by dropping parts complete off a single machine.
In the article, “Tooling Up for Hard Turning," more information is presented about this topic, including tooling considerations for hard turning, and O.D. and I.D. cutting with hard turning.