About us

PURROS Machinery Co., Ltd.

'RBT' is the sub-brand of PURROS Machinery Co., Ltd. focus on Global Standard for Roller Burnishing Tools. Since 2007, we have served more than a thousand customers, until now customers have continued to use our products – a testimony to our high quality. Customers' trust and support are our motivation to advance. We will continue to provide customers with burnishing solutions to meet sizing and finishing needs, with faster production and at a lower cost. Thank you!

Why you should use Roller Burnishing Tools (Roller Burnishing Tool Functions)?

Roller Burnishing Defined:

Roller burnishing is a surface finishing technique in which hardened, highly polished steel rollers are brought into pressure contact with a softer piece part. Roller burnishing replaces grinding, honing, lapping and other expensive secondary operations.
As the pressure generated through the rollers exceeds the yield point of the piece-part material, the surface is plastically deformed by cold flowing of sub-surface material. The result is a mirror-like finish and a tough, work-hardened surface with load-carrying characteristics which make the burnished surface superior to finishes obtained by abrasive metal-removal methods.

Primary Benefits of Roller Burnishing Tools

1. Mirror like surface finish

Surface finish ranging from 0.05 Ra – 0.2 Ra can be achieved easily by using RBT Burnishing Tools.

2. Dimensional Consistency / Repeatability

Very close and consistent dimensional tolerance can be achieved in several thousand components by using RBT Burnishing Tools. Assembly problems are totally eliminated since part dimensions are maintained within tolerances.

3. Single Pass Operation

Since roller burnishing is single pass operation very less cycle time is required to complete the job to required surface finish and tolerance. Hence better results are achieved with less cycle time unlike grinding, honing and lapping.

4. Increase in Surface Hardness of Workpiece

Since Roller burnishing operation is cold rolling process, work hardening takes place on the cold worked surface. Roller Burnishing gives a better wear resistance on the rubbing surfaces thereby the increases the part service life.

5. Reduces the Reworks and Rejections

In most of the operations (such as reaming and boring) there is a chance of maintaining the dimensions under size or over size especially in mass production.
RBT Roller Burnishing Tools can eliminate these problems by keeping necessary stock allowances before burnishing. Exact sizes can be achieved after burnishing process thus reducing the rework and rejection that saves cost and time, in addition to maintaining the promised delivery schedules. Also assembly problems are totally eliminated since part dimensions are maintained within tolerances. Hence reworks and rejections can be eliminated to a great extent at the time of assembly.

Results of Roller Burnishing

After Roller Burnishing one will achieve 100% dimensional consistency, mirror like surface finish, work hardening on the burnished surface. In addition to this rework /rejection is eliminated in the production line. Because of this the cost incurred due to rework /rejection is totally eliminated. Also promised delivery time to customer is maintained. Both ferrous and non-ferrous materials can be Roller Burnished in soft stage.
Gentle hint: Heat Treated components cannot be burnished.

Line up of RBT's Tools

Inside Diameters(Holes)
Outside Diameters(Shafts)
Flat Surfaces
Spherical Surfaces and Contours
Fillets(Radii at Shoulders)
Single Roller Burnishing
Diamond Burnishing
Skive & Roller Burnishing
Rotary Broaching
Chamfering & Deburring