Stainless steel can be as strong as any traditional steel and can retain excellent corrosion resistance for a very long time. There is a wide range of mechanical fasteners made of stainless steel alloys.
Stainless steel can be defined as an alloy of steel, produced by adding nickel to standard low-carbon alloy steel, having a carbon content of 0.3% to 0.5%. At least 10% of chromium has been added to this common low-alloy steel as an alloying agent.
Fair Wind Fasteners deals with various 316 stainless steel nuts and bolts that are meant for marine applications.
SS 316-made fasteners have the following properties:
- Made up of an alloy of nickel chromium molybdenum
- Has got good strength and also excellent corrosion resistant
- The hex bolts can easily be driven with tools and are much stronger because of their shapes
- The minimum yield strength of SS 316 material is 205MPa
- The minimum tensile strength is 515MPa.
- These fasteners are suitable for any applications where high temperature and pressure are needed.
DO’s and DON’Ts of stainless-steel fasteners
1. DO: Select the right grade
There are 2 grades of SS fasteners, you must choose them based on the environment to be used:
- 304: Suitable for normal environment applications
- 316: Suitable for an environment where corrosion is possible. Most suitable for marine applications.
2. DO: Lubricate threads
Leading stainless fastener engineers advise lubricating all types of stainless-steel threads before assembly to lower the possibility of galling.
3. DO: Select the right surface finish
More polished/smoother surfaces provide superior corrosion resistance. This kind of finish can trap tiny particles that weaken the stainless steel’s protective chromium oxide layer, resulting in “tea-staining,” which gives the material a rusty appearance.
4. DO: Consider electropolishing
Electro-polishing or passivating (a certain form of acid treatment) can improve corrosion resistance by deepening the naturally happening protective layer of chromium oxide that gets formed on stainless steel.
5. DO: Create and follow a certain cleaning schedule
Stainless steel products have to be regularly cleaned for removing contaminants (such as salt) and in this way maintain the appearance of stainless steel.
6. DO: Consider exposure to rainwater
Consider possibilities to increase corrosion resistance by choosing a more corrosion-resistant grade so that stainless steel will be protected from rainwater and also in a corrosive environment.
7. DON’T: Contaminate
Loose and embedded iron particles are the most common source of contamination. The following activities can also cause contamination:
- Grinding
- Blasting
- Welding
- Machining
- Filings
- Excessive dust
Avoid them so that it does not contaminate.
8. DON’T: Cause galvanic corrosion
Avoid the contact of 2 dissimilar metals. You must use washers of nylon or rubber materials to avoid direct contact. However, still, galvanic corrosion may occur when one metal has got contaminated after the water passes from one metal to the other.
9. DON’T: Unwittingly buy any low nickel stainless steel
Some proprietary grades that are being offered as 304 or 316 on the market may have high manganese content and low nickel content. These alloys are unsuitable for coastal areas since they also contain less chromium.
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