Stainless bars boast a range of highly valued characteristics, but by far the most important of these is the one that gives the alloy its ‘stainless’ name: corrosion resistance. This is achieved through the alloying process - stainless steel is a metal alloy whose chief constituents are iron and chromium, and to qualify as stainless steel, the metal must contain no less than 10.5% chromium (in practice it’s often slightly more).

Other common ingredients generally present at varying percentages in stainless steel include silicon, carbon and manganese. Further alloying additions for achieving specific applications/characteristics of the finished product are often introduced during manufacture; these might typically include titanium, molybdenum, nickel, copper or nitrogen. The total quantity of alloying ingredients in a finished piece of stainless steel can frequently be as high as 30%.

We’ll talk more about different types of stainless alloys and their respective qualities a little further on in this guide, but when looking to buy stainless steel online - be it bars, rods, or stainless steel tubes, sheets and angles - you should always be aware that the metal is manufactured and graded in many different ways.

This is done in order to meet varying standards of corrosion resistance for use in very specific types of applications and environments, and it’s why you’ll find so many different ‘grades’ of stainless products listed on the catalogue pages of most stainless steel bar suppliers.

Here’s where buying stainless steel rods and bars - or any stainless product, for that matter - can get really confusing. The ‘grade’ of a stainless alloy product denotes precisely what its intended application or environmental resistance will be, and this is dictated by both the specific chemical/elemental makeup of the alloy in question, as well as any finishing or treatment process it has undergone after casting.

As you can probably imagine given the range of options already outlined in this guide, this leaves us with a bewildering number of potential grades of stainless steel (over 150, in fact, although only around 15 of these are especially common in everyday construction use). Worse still, there isn’t even one universal method for grading stainless steels - while there is often a large degree of crossover, specific grading scales do technically vary from country to country!

Stainless steel grading systems are intended to give users an indication of both the subtype of alloy used, and the range of applications a product is therefore suited to. You’ll typically see them written as numbers, occasionally numbers and letters, with a few common examples being:

As we noted in the section above, the one characteristic of stainless steel that’s valued above all others is that it’s impressively resistant to various forms of corrosion, depending on the specifics of how a given stainless steel grade was manufactured.

However, the alloy also has a number of other noteworthy properties that you should always bear in mind when shopping for stainless steel rods, bars, sheets and other products aimed at a specific application or aesthetic. These include: