[Healeys] British car fasteners

[Bob Spidell]

As an aside, there's a WWII story--true AFAIK--about Packard building 
the (fantastic) Merlin engine under license from RR. The Packard 
engineers where aghast to find that the Merlin used over 400 different 
fasteners; they re-engineered the engine to use about 100 (or less).

Another tale I heard once was about an American Air Force team doing a 
flying exhibition in England with F-86 Sabres. One of the inspection 
panels came loose, and one of the ground crew casually walked out, 
closed it and fastened a quarter-turn screw with a screwdriver. The Brit 
military personnel in attendance were astounded; for their planes, only 
a crew chief could tackle such a job, required re-fitting and 
re-attaching several pieces of skin, several different fasteners, and a 
ream of paperwork.

Bob

On 6/1/2020 8:26 AM, Hap Polk wrote:
>
> Curtis,
>
> Thank you for putting together such a definitive treatise on the 
> fascinating history of British threaded fasteners and the industry’s 
> conversion to U.S. standards. The British experience is a precursor to 
> the U.S. slow walking conversion to ISO standards. Looking at 
> Austin-Healey products, one might think that the Brits were more 
> accommodating to having a variety of approaches than their U.S. 
> cousins. Might be a cultural thing.
>
> I, we, would like to read a supplemental discussion of the relative 
> merits of the 55 degree rounded roots and peaks thread design versus 
> the U.S. standard of 60 degree with ‘V’ roots and peaks. What I 
> remember from past discussions regarding the overall performance 
> characteristics of modern thread designs; including thread stripping, 
> pull out strength, and fatigue resistance favored Whitworth first, 
> then U.S. standard, with ISO bringing up the rear. Is that your belief?
>
> Will you possibly in a later effort describe the best uses of the 
> various fasteners depending on the materials being joined, loads and 
> their direction, vibration, load cycling, etcetera in selecting  fine 
> versus course thread; bolt shoulder, head, bearing surface and 
> wrenching method, and the many other criteria that enter into fastener 
> selection.
>
> You added to the points to consider when judging a car’s concours ‘as 
> born’ condition. Thank you. However, would you consider expressing 
> your opinion as to which specific fastened joints a Healey owner might 
> want to use a more modern substitute fastener to make  a more reliable 
> daily driver?
>
> Thank you again for your authoritative contribution.
>
> Hap
>
>

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