Roller burnishing, or surface rolling, is used on cylinders to improve the surface finish of the tubes. Unlike grinding, burnishing is a compressive technique that creates a highly polished surface relatively free from surface ridges or asperites. This more highly polished surface allows seals to operate more effectively.
Burnishing of tubes is undertaken using a tool that resembles a roller bearing, with rollers rotating in cage. However, unlike a bearing, the rollers are generally very slightly tapered so that their surface contact can be finely adjusted.