Things to Know about Stainless Steel Sheet Finishes

Posted by Armstrong Louis on January 18th, 2018

Due to its unique characteristics, like strength, malleability, lustre, durability and versatility, stainless steel has found a strong footing in industrial, commercial and household sectors. The metal is used for various purposes in every aspect of day to day life. One ideal factor that lends to its popularity is the variety of finishes that are available in the market to change the theme of your assignment. They have become an obvious option in kitchens due to its properties like cleanliness, elegant appearance, corrosion resistance, waterproof and rust resistance.

We will take stainless steel sheet finishes into consideration and classify the various kinds that are available in the market and can transform your project from one theme into another with ease. The different finishes are as follows: (Information Credit: www.eurosteel.co.za/index.php/stainless-steel-decorative-finishes/index.html)

• 2B type: This is a bright, cold-rolled finish also known as mill finish.
• No. 3 type: A medium polished surface made by 120-grit abrasive that has a grainy course running from one direction to another.
• No. 4 type: This finish is obtained after treating with a 150-grit mesh abrasive that is brighter than No.3 type but has directional grainy features.
• No. 8 type: Also known as mirror finish, this finish has reflective properties like a mirror that is obtained by using finer abrasives and extensive burnishing.
• Bright Annealed: This is sometimes mistaken to be the No.8 type but it is not as reflective or defect-free as the mirror finish. The sheets are kept under a certain atmosphere and annealed to obtain this finish.

Before choosing a certain type of finish that is required to be obtained, there are some things to keep in mind:

1. It is not known to many that if not treated well, stainless steel may also become corrosive in nature. Contact with carbon steel tooling or an active mating part or heat affected zones on a welded part can cause corrosion issues.
2. Before electropolishing, proper macro and micro deburring are required. Some may need to be mechanically cleaned or treated with vibratory finishing for achieving the desired uniform finish.
3. Rather than just opting for a passivation process, accelerated corrosion tests have shown that electro polishing after passivation makes the steel more corrosion resistant.
4. There are three other polishing processes that can be employed for achieving that pitch-perfect finesse everyone wishes for.

• Manual polishing

This requires a skilled technician to polish the whole surface area consistently and equally for a uniform finish. Electropolishing is the final step after this.

• Mechanical Polishing

This is a costly and time-consuming process that requires a fine grit to achieve the smooth surface. The metal is smeared and moved constantly and uniformly for a long time.

• Blasting

This process uses glass beads, aluminium oxide and sand. The materials are blasted on the surface of the metal under high pressure to remove scales from casts and heat treated surfaces. This process dulls the finish of the metal and needs to be followed up by another polishing process, preferably electropolishing to brighten up the surfaces.

Achieving the right finish is a long process that requires care and skilled technicians who know their ways when dealing with stainless steel.