If you ever walk into any fastener section of the local hardware shop then you will find that the entire aisle is dedicated to various kinds of screws, nuts, and bolts with several drawers having a dozen compartments and each with a certain different bolt, nut, or screw.
If you have a little working knowledge about how to identify marine fasteners or for certain special applications then it can reduce to some extent your confusion.
What are marine-grade fasteners?
All marine grade fasteners will refer to those fasteners that are specially designed for use in the marine industry. They are in fact, very strong and also totally weather/corrosion resistant.
Marine-grade stainless steel will refer to a certain kind of steel, which has Molybdenum added to it. This alloy would mean that the steel will be completely corrosion resistant such as rust and will make it the right choice in any saltwater environment.
How should I select the right fastener to use for my boats?
Before you make this all-important decision, it is important that you should know how heavy your load is going to be that your fastener can handle.
It is necessary to remember that your best choice will almost always be fasteners of the similar material as your components being joined.
Whether fasteners of stainless steel would ever corrode if coupled with aluminum?
They will corrode, and hence you must always avoid this pairing. When stainless steel will come into contact will aluminum where there is a strong presence of a certain electrolyte such as saltwater, then a certain galvanic corrosion process will start.
The best way of avoiding this will be to keep your stainless steel alone and it will last a lifetime.
Bronze, stainless steel, zinc plated fasteners
When boaters congregate around any dock carts to debate the pros and cons of using any oval head metal screw versus any flat-head wood screw, the topic nearly inevitably shifts to the best type of material to use.
Brass with a chromium plating, bronze, or stainless steel? Stainless steel is widely regarded as the greatest all-around fastener material. It is not without reason. Stainless steel provides high strength and corrosion resistance at a low cost, and there are various stainless steels to choose from.
Bronze and plated/coated steels have a place in marine application and should not be overlooked. Bronze can be an excellent option for below-the-waterline applications because it maintains corrosion resistance even if oxygen is absent and is often considered as the least noble type of metal on a boat—meaning it gets along with other materials and is unlikely to react galvanically with the materials that it secures.
Coated graded steel also has a higher tensile strength as compared to stainless steel, making it a superior option for any shaft coupling bolts or other engine parts.
Aside from engine applications, still, stainless steel will be the finest option for many jobs. If the manufacturer has made any recommendations, look for them in any instructions that came with the gear or equipment you are installing.