produce about four mandrels with splines per day, versus the two to three per day we were getting with our old process.” Parts run on the turning centers are primarily mandrels, long shafts with a thru hole of various diameters. They rough turn the mandrel, finish it, and then machine two different types of threads—OD Acme threads and API threads. The Acme threads are on one end and the API threads are on the other end. The last operation is cutting the splines that are spaced at 60° and are 35–36" (889–914-mm) long. The splines are cut after the turning and threading operations.
“Oil Patch parts require tough, rigid, highly flexible machine tools to deal with them.”
JNB is capable of cutting a wide array of splines from straight splining to involute splining by using specialized cut- ting tools on the turret and the live tooling features. The Hyun-
At JNB Machine Shop, a mandrel is fixtured in a Hyundai WIA L700MA turning center with Fanuc 32iM control for rough turning, finish turning, threading, and milling the spline.
dai machines are versatile, and, in the case of the L700MAs, they can mill the splines in the lathe without having to take the mandrel out of the machine. The Hyundai’s can easily hold 0.001–0.002” (0.03–0.05 mm) in tolerance and repeat- ability. These tools have to be particularly durable because of the harsh environments in which they work and the Hyundai