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Stainless Steel Polishing Services

Shaw Stainless is an industry leader when it comes to stainless steel polishing. We offer different grades and types of polishing to meet your requirements. Stainless Steel Polishing can be done either mechanically, chemically, or both. The type of polishing depends on the application. We have experts on hand to help you decide by your application and budget. Shaw Stainless is continuously looking into new technologies for ways to provide the best quality polished products possible and to supply more cost-effective options to our customers.

If you are looking for a consistent surface finish, polishing is a necessary process on mill finish stainless to produce an aesthetically pleasing surface finish. Our diverse equipment allows us to offer a variety of finishes on many different types of products including pipe, tube, round bar, square bar, flat bar, angle, plate, sheet and even fittings.

Our stainless steel polishing technicians are experienced craftsmen that are experienced in different surface finishes. Incorrect polishing can cause distortion, discoloration, work hardening, or loss of tolerances. Extra care is especially required when taking a mill finish up to a #4 finish and higher because of all the steps needed in using progressively finer grits. Polishing is not a race against time. It is having the knowledge that patience is one of the key elements in supplying our valued customers superior consistent quality.

The complexity of the product effects how labor-intensive the stainless steel polishing process is, which determines the cost. Pipe or tube being less labor intensive than, for example, fittings or an inside of angle requiring a hand-held tool being the most complex.

Stainless steel Mechanical polishing is accomplished by utilizing abrasive materials on rotary equipment. This can be achieved by using hand-held tools for difficult to access or unusually shaped parts or automated processes for larger areas depending on project requirements. To achieve a polished surface, a series of abrasive grits are applied in a successively finer sequence until the desired finish or surface roughness is achieved.

Surface roughness is a measure of the texture of a surface. It is quantified by the vertical deviations of a real surface from its ideal form. If these deviations are great, the surface is rough; if they are small, the surface is smooth.

If your surface roughness is critical, a profilometer is used with a diamond tipped stylus that automatically drags across a surface for a set distance and gives the results in many different formats. The most typical are Ra (micro-meters), Ra (micro-inches), RMS, etc.

Standard Surface Finishes of Stainless Steel:

Surface finishes on stainless steel are generally selected for appearance. The degree, extent of forming and welding should be taken into consideration when selecting raw material. You would not want to start with polished raw material that is going to be scratched in process and is going to be final polished anyway. In this instance it is often more economical to use a cold rolled finish material, and then polish.

Unpolished Stainless Steel Finishes

No. 1 Finish: Hot rolled, annealed and descaled. Produced by hot rolling followed by annealing and descaling. Generally used in industrial applications, such as for heat or corrosion resistance, where smoothness of finish is not critical or of importance.

No. 2D Finish: A dull cold rolled finish produced by cold rolling, annealing, and descaling. The dull finish may result from the descaling or pickling operation or may be developed by a final light cold roll pass on dull rolls. The dull finish is favorable for the retention of lubricants on the surface in deep drawing operations. The finish is generally used in forming deep drawn articles, which may be polished after fabrication.

No. 2B Finish: A bright cold rolled finish commonly produced in the same manner as No. 2D, except that the annealed and descaled sheet receives a final light cold rolled pass on polished rolls. This is a general-purpose cold rolled finish. It is commonly used for all but exceptionally difficult deep drawing applications. This finish is more readily available than No. 1 or No. 2D Finish.

BA Finish: (Bright annealed) bright cold rolled and controlled atmosphere annealed to retain highly reflective finish.

Polished Stainless Steel Finishes

No. 3 Finish: A polished finish obtained with abrasives approximately 100 mesh, and which may or may not be additionally polished during fabrication.

No. 4 Finish: A general purpose polished stainless steel finish widely used for restaurant equipment, kitchen equipment, store fronts, dairy equipment, etc. Following initial grinding with coarser abrasives, sheets are generally finished last with abrasives approximately 120 to 150 mesh.

No. 6 Finish: A dull satin finish having lower reflectivity than No. 4 Finish. It is produced by Tampico brushing No. 4 Finish sheets in a medium of abrasive and oil. It is used for architectural applications and ornamentation where a high luster is undesirable; it is also used effectively to contrast with brighter finishes.

No. 7 Finish: A high degree of reflectivity. It’s produced by buffing the finely ground surface, but the grit lines are not removed. It is chiefly used for architectural and ornamental purposes.

No. 8 Finish: The most reflective finish that is commonly produced. This finish, is obtained by polishing the stainless steel with successively finer abrasives and rubbing extensively with very fine buffing rouges. The surface is essentially free of grit lines from preliminary grinding operations. This stainless finish is most widely used for press plates, as well as for mirrors and reflectors.

Stainless steel sheets can be produced with one or two sides polished. When polished on one side only, the other side may be rough ground in order to obtain the necessary flatness.

* Standard stainless stock polished finish is between 100 - 180 Grit (#3 to #4)

Stainless Steel Polishing

Circumferential Polish

Brushed Finish Polish

Polished Stairs

4 Foot Wide CNC “Wet” Sander Flat Polisher

How A Profilometer Travels Over The Surface Deviations

Polished Finishes

#Finish

RMS

30-45

25-40

18-30

15-25

14-20

12-18

5-9

4-8

1-5

0-4

Surface Measurements Comparison

RMS
(Micro-inch)

RMS
(Micron)

RA
(Micro-inch)

RA
(Micron)

Grit Size

2.03

1.8

1.47

1.32

120

1.2

1.06

150

0.86

0.76

180

0.43

0.38

240

0.36

0.3

320

Grit Size Comparison

Grit Size

Avg Particle Size (in)

0.2577

0.2117

0.1817

0.1366

0.1003

0.083

0.0655

0.0528

0.0408

0.0365

0.028

0.02

0.017

0.016

0.0131

0.0105

0.0085

100

0.0068

120

0.0056

600

0.00033

900

0.00024