Metal Finishing on Stainless Steel Sanitary Systems
Stainless Steel Finishing
Typical Stainless Steel Mechanical Finishes
Mill Finish A Mill FinishThe basic finish that comes on most stainless steel flat products. It’s the starting point of more advanced finishes, with an Ra of more than 100 microinches.
2B FinishThis common stainless steel finish is often used in chemical and food applications, not as stringent as sanitary applications. The typical Ra range of 40 to 15 microinches.
No. 3 Finish120 grit abrasive paper is typically used for the final step in producing a No. 3 finish. Its Ra is in the range of 36 – 58 microinches.
No. 4 FinishOften used in more advanced, sanitary applications, a 150 grit abrasive is used. The Ra range is 29 – 40 microinches.
No. 4 Dairy / 4A FinishFor many advanced food processing applications, the number 4 Dairy(or 4A) finish is required. It uses a 180 grit and has a Ra range of 18 – 31 microinches.
Stainless Steel Chemical Finishes for Food, Bio, and Pharmaceutical ApplicationsAnderson Dahlen has produced stainless steel components to an extremely wide range of finishing specifications. Our customers are continuously impressed with the high quality of our finished products. We can meet any surface finishing requirement with speed, repeatability, and be cost effective.
Bead BlastedBead material such as glass or ceramic is used produce a textured surface with a soft satin appearance and low-reflectivity. Bead size can determine the finish appearance and corrosion resistance. Ra greater than 45 can be achieved. Typically used in structural applications and would not meet sanitary food processing finish requirements.
PassivationThis removes excess iron from stainless steel surfaces. Usually and acid-based solution is employed. No metal is actually removed and this has very little impact on the Ra value of the surface.
Pickle PassivationIn this process, the part is soaked in a bath with pickling solution, typically nitric-hydroflouric acid. Metal contamination can be removed as well as removing any scales remaining from heat treating. This can be used for slight improvements in Ra value as well.
ElectropolishingThis electro-chemical process that does a controlled removal of surface material. An acid bath and DC current are used in parallel produce a mirror like finish. In some cases, up to a 50% improvement in surface finish Ra can be achieved.
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- (1) Pal Industries 96.00in table, 6.00in wide belt
- (1) Pal Industries 120.00in table, 6.00in wide belt
- (1) Pal Industries 144.00in table, 6.00in wide belt
- (1) Arrow 10hp, 2:spindle
- (2) Time Saver 20.00in x 16.00in opening
Glass Bead Blast
- (1) Empire Abrasive booth, 36.00in x48.00in
- (1) Enviro Systems booth, 168.00in W x 240.00in L x 240.00in H
- (1) Edge deburring – 7 gauge capacity
- (2) Quincy 50hp screw-type w/dryer