If you’re trying to optimize metalcutting speeds, especially in difficult-to-machine materials, “Heat transfer is the name of the game.” That’s the summary offered up by Ranajit Ghosh, manager of applications R&D and growth for Air Products (Allentown, PA). “Most heat from a machining operation exits through the chip, but some transfers to the cutting tool, toolholder, machine spindle and workpiece. Heat buildup in the cutting tool causes thermal softening of the edge, which is why we often have to employ coolant.”