These were in a recent pile of auction plunder. Two of the same wrench, so you see both sides. The big end measures about 13/16" (21mm). On one side of the wrench that's labeled 1/2 BSF. On the other side the same thing is labeled 7/16 W.
At the small end the size is 23/32" (18mm). That's labeled 7/16 BSF and 3/8 W. What are the units of measurement here?
The W is Whitworth. When I was living in Holland and owned the Austin, I was in London one day for my work. High on my list was to go to a hardware store and buy a set of Whitworth wrenches so I could work on the car more easily. (Our British forum participants would probably say that I went to the ironmonger's to buy a set of spanners, but we know better.... )
These are the old British thread sizes that were used before the 'Unified' sizes adopted after WWII (UNF and UNC). Some British cars (and especially bikes) continued to use these threads right up to the 1960s.
Unlike the Unified series, which has spanners marked with their 'Across Flats' dimension, the 1/2 BSF spanner fits the head of a 1/2" diameter British Standard Fine bolt or nut.
BSW is British Standard Whitworth - the coarse thread. The spanners here are confusing because the heads of BSW bolts and nuts used to be one size larger than their BSF equivalent. So your 1/2 BSF spanner would also fit a 7/16 BSW bolt head! Many spanners (like yours) were marked with both the BSF and BSW heads that they fit.
Later BSW bolt heads were the same as their BSF equivalent.
Don't you just love standards! There are so many to choose from!
Standard, go look at the brass pipe fittings in a hardware store some time.
My brother has a 35 Rolls. Maybe he can use them.
I've heard the British had a lot of problem with the quality of their tanks in WWII. Maybe why.
Probably! Back when I worked in a RR & Bentley restoration shop (that I later turned into a T shop, just before it closed!) we used lots of those!
From the markings on the wrench I would guess they came with a Lister Diesel, maybe a power plant.
Another oddity was the 55º thread pitch used on Whitworth instead of the 60º common on this side of the pond.
Makes a good case for the tool us old folks call a Crescent Wrench, right? (Nowadays called an "adjustable wrench".)
Please don't criticise BSW threads and their 55 degree angle. I'm helping restore an old rope works, built around 1890 and abandoned in 1968. The building has a (leaky) roof, but no sides. We took 11 pulleys off the main line-shaft for sand-blasting. Each pulley has 4 large BSW bolts and 10 or 12 smaller (3/8) countersunk slotted-head screws and nuts. We only had to cut 3 small nuts (didn't damage their screws). The rest came undone with spanners and a screwdriver after 120 years!
You need a minimum of 3 crescent wrenches
One for English - one for metric and the last for whitworth bolts
British aircraft continue to use WS wrenches and bolt sizes. Not only are the bolts and wrench sizes odd, the hydraulic and oxygen plumbing is also unique and fraught with oddness. Coin slot screw heads and other hardware invented for the Lancaster Bomber and Hawker Hurricane fighter interceptor are probably coming from WWII era parts sources.
Hawker Beechcraft is in bankruptcy right now, so it could be near the end of the line for a lot of oddball hardware and plumbing fittings.
Fred, 3 will not crack the mustard. You have forgotten those needed for left hand threads. And then there are the different ones for left handed mechanics, like left handed scissors. If you are not very careful you could be hit with a lawsuit for discrimination against those with sinister tendencies.
Allan from down under
I bought a pair of left handed scissors once to cut brass, sometimes I needed to cut from a specific side of the work, and the left handed scissors worked great, but they became mixed up in my wife's stuff, and she grumbles every time she grabs them, I have left them there because I no longer work with brass, and it is fun to watch her try to use them.
Do not forget the need for a Crescent hammer in every tool box
.......or as I was taught in a Ford tractor school in the mid 70's.......BFH or big swinging press!
Hawker Beechcraft is out bankruptcy and has been sold.