• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Geoffrey Healey said:

Share this page

jlaird

jlaird

Great Pumpkin
Country flag
Offline
"After the second World War, we changed over to a unified system of screw threads, fixings, nuts and bolts that was compatible with the Society of Automotive Engineers' standard of use in the USA. This change, a wise one , cost a lot of money but it did birng a degree of standardization to the ndustry and resulting benfits to the customer. All Big Healeys and Spridgets were built using unified SAE standards, while the Jensen Healey was metric.

Somehow I missed that in the past. No wonder I had trouble figureing out fastenings.
 
Yes.
But some older (pre-war) parts that continued to be made after WW II(especially some SU carb parts) continued to use the Whitworth threads. And the wrench sizes were continued on some older-designed parts for a while too. Whitworth threads use a 55 degree thread angle so they are almost impossible to tell from the normal 60 degree SAE (and ISO) threads.
 
Back
Top