Case Study: Burnishing a Master Cylinder Piston


A customer of ours was manufacturing master cylinder pistons made of 3415 case hardening steel using a Doosan Lynx 220-LSY CNC Lathe. The part required a surface finish of 12 Ra microinch (0.3 Ra) or better on the outside seal diameter.
Before we got involved, the customer was sub-contracting another company to grind these parts down to achieve the required surface finish, since they could not achieve the correct surface finish using a turning insert.
Here was their original process:
surface finish from a roller burnishing tool


Once we assessed their operation, we recommended that they use an Elliott Tool Technologies S2488-00M Single Roll OD Burnishing Tool
single roll roller burnishing tool
surface finish after using a burnishing tool


The single roll burnishing tool produced a surface finish of 7 Ra microinch (0.18 Ra) or better. The parts could be made all in-house, eliminating the need for expensive sub-contracting to grind the pistons. The new process only required one set-up, saving our customer lots of time and money.
Our team has worked with thousands of different applications, if you have a question or are wondering if your application can be burnished, contact us here.