SAE numbering system for steel

[wilby08]

Hi can anyone tell me where you would find SAE 8195 and SAE 4035 steels on an aircraft or what these steels are usually made into etc.
Thanks

[Capt Casper]

1= Carbon steels
2= Nickle steels
3= Nickle Chrome steels
4= Molybdenum steels
5= Chromium steels
6= Chrome vanadium steels
7 ??
8=Nickle Chromium-Molybdenum steels
9= Silicon - Manganese steels

2nd number= percentage of main alloy
3rd and 4th number= carbon content in points.

Alloying and heat treatment are combined to achieve desired properties - Hardness, toughness, suitability to weld or machine etc.