• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!

    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

New Grade 12.9 Socket Head Bolts

vettedog72

Jedi Knight
Offline
I saw an advertisement for "New Grade 12.9 Socket Head Bolts" and wondered what I have missed. I am still thinking grade 8 is the recognized highest grade bolt for engines. Do socket head bolts have a separate grading system?
 
That sounds like the grading system used for metric bolts.
With metrics, they generally run from 8.8 to 12.9.
Those grades are based on a different set of parameters than the SAE system.
Jeff
 
Jeff is correct 12.9 is the metric equiv of SAE grade 8. SAE spec also has grade C and I've also seen 9 in race catalogs.
 
Back
Top