SAE steel grades

The Society of Automotive Engineers (SAE) designates SAE steel grades. These are four digit numbers which represent standards for steel specifications. Prior to 1995 the American Iron and Steel Institute (AISI) was also involved, and the standard was designated the AISI/SAE steel grades. The AISI stopped being involved because it never wrote any of the specifications.Citation | last = Bringas | first = John E. | title = Handbook of Comparative World Steel Standards: Third Edition | publisher = ASTM International | page = 14 | year = 2004 | edition = 3rd. | url = http://www.astm.org/BOOKSTORE/PUBS/DS67B_SampleChapter.pdf | isbn = 0-8031-3362-6]

Carbon and alloy steel

Carbon steels and alloy steels are designated by a four digit number, where the first two digits indicate the alloying elements and the last two digits indicate the amount of carbon, in hundredths of a percent by weight. For example, a 1060 steel is a plain carbon steel containing 0.60 wt% C.

Stainless steel

*200 Series: austenitic chromium-nickel-manganese alloys
*300 Series: austenitic chromium-nickel alloys
**Type 301: highly ductile, for formed products. Also hardens rapidly during mechanical working.
**Type 303: free machining version of 304 via addition of sulfur
**Type 304: the most common; the classic 18/8 stainless steel.
**Type 316: the next most common; for food and surgical stainless steel uses; alloy addition of molybdenum prevents specific forms of corrosion. 316 steel is [http://alleghenyludlum.com/ludlum/Documents/316_317.pdf more resistant to corrosion than 18-8] stainless steels. 316 steel is used in the handling of certain food and pharmaceutical products where it is often required in order to [http://sandmeyersteel.com/316-316L.html minimize metallic contamination.] 316 steel is also known as "marine grade" stainless steel due to its increased ability to resist saltwater corrosion compared to type 304. SS316 is often used for building nuclear reprocessing plants.
*400 Series: ferritic and martensitic chromium alloys
**Type 408: heat-resistant; poor corrosion resistance; 11% chromium, 8% nickel.
**Type 409: cheapest type; used for automobile exhausts; ferritic (iron/chromium only).
**Type 410: martensitic (high-strength iron/chromium).
**Type 416: the most machinable stainless steel; achieved by the addition of extra sulfur which reduces corrosion resistance. Often used for "stainless" rifle barrels
**Type 420: "Cutlery grade" martensitic; similar to the Brearley's original "rustless steel". Also known as "surgical steel".
**Type 430: decorative, e.g., for automotive trim; ferritic.
**Type 440: a higher grade of cutlery steel, with more carbon in it, which allows for much better edge retention when the steel is heat treated properly.
*500 Series: heat resisting chromium alloys
*600 Series: martensitic precipitation hardening alloys
**Type 630: most common PH stainless, better known as 17-4; 17% chromium, 4% nickel

References

Notes

Bibliography

*cite book |last= Oberg |first= E. |coauthors= et al. |title= Machinery's Handbook |edition= 25th edition |year= 1996 |publisher= Industrial Press Inc

ee also

*Steel grades
*ASTM International
*EN standard
*Unified numbering system