Q: What is the difference between alloy 330SS and 310SS bolts?

A: Good question. Alloy 330 and 310 are fairly similar however there are some differences. Alloy 330 fasteners offer high temperature protection, oxidation and carburization resistant to 2100°F whereas 310SS maxes out at 2000°F. In addition, alloy 330 bolts provide improved protection to cyclic temperature conditions of extreme heating and cooling over 310SS. Finally, 330 offers 85ksi of ultimate tensile strength compared to 70 of 310SS fasteners. So why consider 310 SS? 310SS is more economical than alloy 330 bolts, however 330 is a higher performing in all other areas.

Q: Can you tell me the difference between alloy 330 and 310 stainless fasteners? I’d like a more economic alternative to the 330 but didn’t know if 310 stainless could be used instead. I have extreme cyclic conditions running to about 2000F?

A:
If cyclic conditions are a concern you may want to stick with the alloy 330 bolts to be safe. 310 stainless steel fasteners are more economical, than 330 but with slightly less strength and temperature resistance. For these alloys the primary difference between them is their ability to perform in thermal cycling situations. Alloy 330 bolts are known for their ability to perform in these cyclic conditions of heating and cooling. In terms of operational temperature limits these materials are similar with 310 stainless steel bolts having a max usability of 2000F where alloy 330 bolts can be used up to 2100 F.