10.9 vs 8.8 Grade Bolts

[danicortes22]

What is the difference between 8.8 and 10.9 grade steel? Which one performs better under cold weather? Is there something I can reference?

Thank you,

 

[Allen]

What is the application? what is cold weather temp?
10.9 is more stronger
Cold weather will shrink both the bolt&nuts and the components attaching, if you ONLY worry about loosening consider using spring/lock washers.

see the chart from Mc Master

 

[edison123]

The first digit is the ultimate strength of the material and the second is the ratio of yield stress to ultimate strength. Grade 8.8 bolts have an ultimate strength of around 800 N/mm2 (MPa) and a ratio of yield/proof stress to a yield strength of 80% i.e, 640 N/mm2 (MPa).

Extreme cold weather would require special bolts, I guess.



Muthu

http://www.edison.co.in

 

[desertfox]

Hi

Look at this site:-

http://roymech.co.uk/Useful_Tables/Screws/Strength.htm

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Korichnevijgigant]

Not sure what you mean by "low temperature" but ASTM A320 (iirc) is for low temps, I used that once working a LOX system