# What is the difference between 321 and 304 stainless?

**URL:** https://forums.speedlife.net/t/what-is-the-difference-between-321-and-304-stainless/42867
**Category:** NYSpeed Automotive
**Created:** [February 3, 2008, 9:48am UTC](https://forums.speedlife.net/t/what-is-the-difference-between-321-and-304-stainless/42867 "2008-02-03T09:48:25Z")
**Posts on this page:** 1
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### Author: ![mike125k](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/mike125k/32/7282_2.png) [@mike125k](https://forums.speedlife.net/u/mike125k)
#### Post date: [February 6, 2008, 4:08am UTC](https://forums.speedlife.net/t/what-is-the-difference-between-321-and-304-stainless/42867/9 "2008-02-06T04:08:55Z")

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> [@OfficerK](#):
>
> what is the rating number actually mean? It can’t be an arbitrary number. Something to do with the particular alloy?

yes. it has to do with alloying elements are present.

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