While there are more than one hundred different AISI (American Iron and Steel Institute) chemistry grades of stainless steel, the most commonly used in commercial fasteners (nuts, bolts, washers, fittings) are types 18-8 and 316. "18-8" is short-hand for 18% chromium and 8% nickel. This alloy content is found in types 302,303, and 304 stainless steel. While they offer a high degree of corrosion resistance, they are slightly magnetic. So don't be fooled just because your stainless washers stick to your magnet. Also, there is a small presence of iron in 18-8 fasteners, so they can corrode in severe conditions. 316 stainless generally offers better corrosion resistance and is even referred to as "marine grade stainless," but it is not resistant to warm sea water. Here at Hillco Fastener Warehouse, 99% of all stainless steel fasteners we sell are 18-8, which is sufficient for pretty much all street rod or other automotive projects, in terms of corrosion resistance.

Contrary to popular belief, and probably the most common misconception about fasteners held by our customers here at Hillco, stainless steel fasteners are not very strong. Now, please don't confuse strength with toughness. Anyone who's ever attempted to drill or cut a stainless bolt knows how tough they can be. But for purposes of this article, let's understand that strength refers to tensile strength. A type 18-8 or 316 stainless steel bolt typically has a tensile strength of around 80,000 psi, which is only slightly stronger than a Grade 2 bolt. If I had a nickel for every customer who came to me explaining that he wanted to use stainless steel bolts in place of his stock suspension bolts, I'd be a rich man. But, if I sold them to them, I'd be a poor man due to being sued for selling them weak bolts! There are other types of high strength stainless bolts that are now available for such applications, but they are usually a special order item, as they are too expensive to keep in stock. So, if you need something strong that will not rust, call us and we'll help you find exactly what you need.

Also important to know when using stainless steel fasteners is that they tend to gall, or cold weld. I also wish I had a nickel for every customer that came to Hillco claiming "You sold me the wrong nut. Look, it stuck to the bolt, and I had to break it to get it off!" I then point to the signs posted everywhere recommending the use of anti-seize to prevent galling. This is where I usually hear them say "Ohhhh. So that's what anti-seize is for." We recommend using nickel anti-seize (ND Industries Vibra-Tite part # ND90704, a 4-oz bottle for $9.50). Think of it as cheap insurance for your stainless steel nuts and bolts. You'll spend a lot of time breaking, grinding, and cutting off bolts if you don't use anti-seize.