Steel is just one of several materials used to make fasteners; others include titanium, plastic, and even rarer metals. In order to more precisely define alloy combinations, hardening processes, etc., many materials are subdivided into several classes. Some materials can also be coated or plated in a number of ways to improve corrosion resistance or to give the fastener a different look.
Because of variations in strength, brittleness, corrosion resistance, galvanic corrosion characteristics, and cost, fastener material might play a role in the selection process.
It is recommended that while changing fasteners, you use identical ones. It's not always secure to replace a weak bolt with a strong one. Bolts with a higher hardness level are often more brittle and may break under certain conditions. Additionally, the bolts on certain apparatus are deliberately intended to break before the expensive or crucial components. As an additional consideration when switching fastener materials, galvanic corrosion must be taken into account in locations with salt water. Please refer to the Stainless Steel Fasteners page for further details.
Stainless steel, sometimes known simply as "steel," is an alloy of low-carbon steel and chromium. Due to its low cost, stainless steel has excellent corrosion resistance. The metal's natural corrosion resistance means it will retain its protective coating during installation and usage.
There is a widespread misunderstanding that stainless steel is far more durable than standard steel. In reality, many stainless steel alloys are incapable of being toughened by heat treatment because of their low carbon content. Therefore, stainless alloy bolts are marginally stronger than unhardened (grade 2) steel but substantially weaker than hardened steel fasteners. Stainless fasteners can gall, or seize up during installation if proper care is not followed.
Though certain types of stainless steel fasteners will be mildly magnetic, most are far less magnetic than their ordinary steel counterparts..
In the context of stainless steel, "18-8" refers to any alloy with a chromium-to-nickel ratio of around 18:8. Most hardware will have this classification, which indicates that it is made of stainless steel. In our Material Grade Identification and Properties Chart, you can learn more about the characteristics of 18-8 stainless steel Fasteners.
Stainless Steel 316 Fasteners
Grade of 316 stainless steel fasteners that are exceptionally resistant to corrosion. Perfect for situations with salt water and bleach. Definitely more costly than 18-8.
Stainless Steel 410 Fasteners
A Stainless Steel 410 fastener that is harder than 18-8 stainless steel, but not as resistant to corrosion.