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,

What are you securing to what....

Also how cold?

8.8 and 10.9 refer to bolt grades as per BS EN ISO 898-1.

In terms of chemical composition, the specs in the above standard are very wide, so a range of carbon/low alloy steels can be used.
8.8 has a tensile strength on ~800MPa nominal, and a 10.9 is ~1000Mpa. this means you can tighten a 10.9 bolt more and get a higher clamping force. The differing mechanical properties are generally achieved by different heat treatment processes rather a difference in composition.

How low is low temperature? There's unlikely to be any great difference in mechanical performance in uk outdoor temperature ranges, but that is more dependant on the steel used than the grade of bolt.

if you have a more specific question i am happy to answer it. It may help if you tell us why you're asking, and what you hope to achieve.

Andy

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Originally posted by 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,

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