17-04-2022, 11:10 AM
(16-04-2022, 05:35 PM)Denis Sweeney Wrote: When I first purchased Ruby I bought a new set of Whitworth spanner’s, none fitted.
After some digging around I found information that indicated that dimensions of pre war Whitworth nuts and bolt heads were larger than post war having been reduced in size during the war to reduce steel usage, I believed this to true, but am happy to be corrected.
Probably because the nuts and bolts holding your car together have been renewed over the years, with whatever the mechanic had in his workshop.
The "change in size" that you refer to is the fact that, after WW 1, better quality steels were available which meant that, where a 1/4" bolt for example, had a 1/4"WW hexagon, this was reduced to the next size down, i.e. 3/16"WW.
After WW2, the government of the day decreed that British Industry should give up its Whitworth and BSF standards and adopt a new "Unified" sizing, which was, in effect, a re-packaged American thread plan. These sizes are the A/F (Across Flats), inch sizes that were used from 1950 - 1970. The Government then inflicted another well thought out change and decreed that, from 1965, British Industry should dump the recently introduced Unified system and adopt ISO Metric threads.
Politicians? What do you expect from a bunch of arts graduates? There's not an engineer among them.