Definition - What does Fastener mean?
A fastener is an important hardware device used in many engineering-related applications that mechanically join or fix two or more objects together. They are considered to be an alternative to welding.
Industrial fasteners are constructed from any of the following materials:
- Stainless steel
- Carbon steel
- Alloy steel
Corrosionpedia explains Fastener
Because fasteners are made from steel they are subject to corrosive attack during their service or operation, so designers must keep this in mind when designing a fastener application.
Generally, fasteners are constructed from stainless steel grades such as 200 series, 300 series and 400 series. Stainless steel items tend to corrode by galvanic corrosion, pitting corrosion or sometimes another type of corrosion due to harsh industrial environments.
Galvanic corrosion refers to the corrosion damage that occurs when two different metals are electrically connected in an electrolyte, where the more noble metal is protected and the more active metal tends to corrode.
Pitting corrosion occurs when the metal's surface has a corrosion-protective film, but also has some minute holes or defects on the surface. Corrosion occurs on these holes when the metal comes in contact with an acidic environment and further deepens the holes, weakening the metal from the inside.There can also be other types of corrosion unless the fasteners are coated or protected with a corrosion-proof paint or coating.
The Corrosion Properties of Aluminum and Its Alloys