roller burnishing tool

Recently a manufacturer of class 8 truck steering components wanted to increase the tool life for their burnishing operation on a front axle spindle. They needed to burnish a section on the spindle that required a surface finish of 0.25-0.50 u-meter Ra (10-20 u-inch Ra). The material was 4140 steel hardened to 47-50 Rc. The current burnishing manufacturer’s tool had a steel roll which only lasted no more than 300 parts. This caused the machine to be shut down so the rolls could be changed out which was about every two days. This disrupted production slowing the delivery of finished product to their customer.

Monaghan Tooling Group was called to look at the application. After reviewing the surface finish requirements with the manufacturing engineers a S2548-00 carbide roll burnishing tool was recommended to the customer. The challenge was the part hardness. The carbide roll had the same corner radius as the previous competitor’s roll so it fit right into the programmed path. Because the carbide roll was harder than the steel roll, the feed & speeds were increased resulting in less cycle time.

A team from Monaghan Tooling came into the manufacture’s plant to review the operation and train the manufacturing engineer how to use the burnishing tool.

After a quick exchange the S2548-00 tool was installed in the lathe turret and the CNC program was updated with the new faster speeds and feeds. Proof is in the pudding as the old saying goes and the first part off the machine looked great and was in spec.

To improve the results even more a small tweak was made to the tool’s pre-load to increase the burnishing pressure and make an even smoother finish.

roller burnishing tool

Any tool can make two good parts. The real test would be in how long the tool would last before the carbide roll would have to be re-ground and re-finished. Almost three months after installing the S2548-00 carbide roll burnishing tool and burnishing 1000’s of parts the manufacturer has not had to make any adjustments at all and is very happy with the reduced cycle time, increased throughput, and improved quality.