Rolls Royce Toolkit Wrench

[j.a.f.e.]

Stumbled on this little gem a long while back. It is an F9799 DOE marked 1BA x 1/4. It was part of the toolkit from a Rolls Royce model 20/25 made from 1929 to 1936. At that time RR included a fairly extensive toolkit in a fitted case.

I just looked up the value of this one and it seems they range from about 30 pounds (I believe a repop) to about 85 pounds - currently pounds to USD are about 1 pound to $1.24. Not sure when the prices are from but that is a lot for a little scrap of metal.

You cannot view this attachment.You cannot view this attachment.

[goodfellow]

1BA x 1/4  -- BA refers to British Association thread standard, and the 1/4 is the size. BA was mostly used for instrumentation industry fasteners, but what actually is meant by 1BA? are the measurements shank diameters? because the 1/4 doesn't look like a 1/4"AF size. Any ideas on what that 1BA x 1/4 system actually means in terms of SAE or even Whitworth standards?

[j.a.f.e.]

No idea no experience with British systems. The openings on the 1BA side is 3/8 and the 1/4 side 7/16 so 1/4 could be the shank diameter.

[goodfellow]

No idea no experience with British systems. The openings on the 1BA side is 3/8 and the 1/4 side 7/16 so 1/4 could be the shank diameter.

yeah -- shank diameter is probably right. That's pretty rare since most common British systems used the head diameter (as in "AF" = Across Flats) as a measure -- British Whitworth for instance. But that wrench is still intriguing because the BA type fasteners were usually found in highly detailed and very small precision type of instrument and machine applications. BA sizes like those indicated on your wrench are far from "precision" sizes. Maybe it was a Rolls Royce thing where they manufactured certain subsystems along a BA standard.

Cool tool and a cool mystery --

[j.a.f.e.]

I can't find the specific application this was intended for other than the general it was part of the toolkit. Knowing that might be a clue as to the size marks. All the tools in the kit were intended for specific applications. The same tool kits might have been originally fitted to the earlier Silver Ghost.