Burnishing

 

What Type of Parts are Good Candidates for Burnishing?

Burnishing is the deliberate effort or intentional deformation of a surface as a result of sliding or moving contact with another surface or object, with the aim of making the surface shine, improve size, shape or harden the surface e.g. in the making of the pivot and pivot holes for long-lasting bearing surfaces in manufacturing of wrist watches and clocks. Burnishing may lead to polishing but polishing is never burnishing and are quite different. Both processes are targeted at getting a shinny smooth finish. The burnishing process is commonly used by manufacturing companies and also usually done in woodwork, pottery, and also in relief printing.

Designing Parts for Burnishing

Designing parts for burnishing is as difficult as burnishing itself. For instance, to design a pivot for a cuckoo clock, it’s very important to pay close attention to the shape of the pivot in relation to the pivot hole. A craftsman or a watch maker should make a choice between a flat pivot or a barrel shaped pivot. As in the making of cuckoo clock, it is better to design the pivot barrel shaped since it will contact the pivot hole in small area. It is important to use lubricants in the process of burnishing. To burnish a clock pivot, the craftsman or watch maker needs a burnishing machine, a pivot file, lubricants and a lathe machine.  Some burnishes usually come with pivot file matted to it.

To start burnishing, start with a well polished and straight pivot. There are usually two methods, over the top and underneath. Start with low pressure and low speed and then work up to high pressure and speed. Place the pivot on top and apply a low pressure with your hand as the lathe spins.