You know when you're searching for an uncommon tool and eventually you buy a decent one, but it doesn't quite do everything you need, so you keep looking and sometime buy another? Then the whole cycle repeats itself until you have several similar tools?
Well it keeps happening to me with BA spanners and sockets. I bought a set of open-ended BA spanners when I was working on a vacuum pump a couple of years ago. Then a bit later I was working on a scientific balance which had some delicate brass BA locknuts. So I ended up with two sets of open-ended BA spanners.
Then I needed to tighten terminals on several motors. The open-ended spanners don't fit very well, so I ordered some BA box spanners. Unfortunately the set was incomplete when it arrived, so I called the old guy at the tool company. He apologised and said that someone else's set had contained a faulty spanner, so he replaced it with one from another set, then forgot about it. The replacement didn't turn up, so I called the guy again and he said the manufacturer was in difficulty and hadn't supplied him. A few months went by and I called the company again, but didn't get the knowledgeable old guy. It turned out that he had passed away. Poor chap.
So I bought some new old stock BA sockets on eBay. Only I screwed up. They were advertised as "BA sockets, 1/4" hex drive". I assumed it meant "BA hex sockets, 1/4" square drive", but no, they are actually hex drive. My fault. They're quite a nice set, though, and they were cheap. They come with a handle which looks like an Allen key, but I was hoping to be able to use a screwdriver-type ratchet handle with them. What do you call a screwdriver-type ratchet handle which fits 1/4" hex drive sockets, I wonder, and where might one find such a tool?
Ah, the joy of hunting for tools (it is quite fun, actually).