Whats the difference between SS solids? (The numbers)

My yard board has SS listed and they are all different numbers like 301, 306, etc. Anything I've ever taken is was bought as 301. How can you tell if you have something different? Is it by item? like, only certain items are made with certain number SS?

The yards I use don't go buy the numbers, if the magnet dosn't stick and it sparks when hit with a grinder it goes in the ss bucket. Sorry I couldn't be of more help.

I know next to nothing about stainless steel. But someone threw out a bunch of stainless steel compression fittings a few weeks back, so I did a little Googling. The fittings were all marked with 304 and 316 (if I remember correctly). Not that this article helps you much with the yards (and how they determine the difference in grades), but >>> SAE steel grades - Wikipedia, the free encyclopedia

Originally Posted by happyscraper

The yards I use don't go buy the numbers, if the magnet dosn't stick and it sparks when hit with a grinder it goes in the ss bucket. Sorry I couldn't be of more help.

My local yard does the same thing. However, if I suspect I have anything better, I'll save it for a trip to the "bigger" yard, where they can have someone look at it and determine if it's worth more to them or not.

I had a bunch of SS 316, the only way I knew it was 316 was because the compression fittings used to join it said so. From my googling what I found pointed towards the different numbers not being of greater or lesser quality, but of having different makeup characteristics(ingredients), giving them differing qualities in differing environments. I am also certain if it is still a usable product, go with Ebay or Craigslist for FAR more than scrap value

Huh. Thanks everyone for all the replies. It just had me wondering since there was 5 or 6 ''numbers'' of SS listed. I don't know why today of all days it bothered me enough to ask about it!

Thanks PFSNewb for the links, that does explain quite a bit

There is 200 series SS high chrome content low nickel content and high steel content. 300 series 5 to 10 percent nickel 20 percent chrome balance steel. 400 series low nickel content usually 2 percent or 3 percent and some chrome and a high amount steel in it. Anything with more nickel then that is going to be a high temp alloy example hasteloy x, inconel, monel, cobalt, etc.

Ahhhhhhhh......ok, now I know what those high temp alloys are! Thanks PSP!

304 Stainless(18/8) is of course the most common and basic stainless in which most yards will buy at one price... 301 stainless has about 2% less nickel in it and will have a slight magnetic draw to it. Because most 30 is usually some kind of stripping it is thin and will appear to be more magnetic than it is. Most yards should pay 304 price for it in normal amounts. 316 has 2-4 % molybenum in it making it much more valuable upwards of .40 cents /lb . You can tell the difference between 304 and 316 by the spark as the 316 will have a distinct starburst at the end but it takes a known piece to really get used to what you should look for. MAny stainless items are marked in code. astm or pwa numbers and screws usually have numbers on them which you could look up. Hope this helps a bit

Grab there are also a few other elements I left out of the other grades to because they are such a small amount its not worth mentioning. For those who really want to know about stainless I would suggest they Google stainless grades and learn as much as they can about them. I can virtually identify any metal just by looking at. 304 vs 316 can easily be identified by how much more shine it has then 304. Scratch tests work to along with a grinder really help with identifying materials that have nickel in them. I hope that helps.