CRAFTSMAN 1/2 - 3/8 UNIVERSAL JOINT

[ken w.]

I found this in my garage while cleaning out. It's a Circle U 1/2" - 3/8" Universal Joint. First time I ever recall seeing one of these.

 

[bwringer]

So how are you supposed to...

Um, what situation would this...

Hmmm...

I'm trying to make this make sense. Does that 1/2" square come out?

 

[four.cycle]

^ I think you've got a 1/2" square drive coupler jammed into a wobbly socket.

one of these:

 

[Private Lugnutz]

^ I think you've got a 1/2" square drive coupler jammed into a wobbly socket.

It does look that way. But one with little tabs that function as stops, so it can't be inserted too far, as shown on the screwdriver and uni joint hex drive plugs in the photo below.

 

[Private Lugnutz]

Note, though, that makes the female opening a 1/2" square, with the 3/8-inch square male drive stud on the other end of the swivel intended for 3/8-inch drive tools. A 3/8-inch drive swivel socket with a 1/2" square service opening would be odd for a mid 1940's era socket set, suggesting that it still is some kind of 3/8-inch drive male to 1/2-inch drive female universal joint. Which is still brow furrowing. I have never seen one of those before.

 

[d42jeep]

^ I think you've got a 1/2" square drive coupler jammed into a wobbly socket.

one of these:

I’m with BK on this one.
Or possibly one of these.
-Don

 

[3baygarage]

It's a Plomb made u joint with a ratchet plug in it. From here both look 1/2" though.

 

[Private Lugnutz]

It's a Plomb made u joint with a ratchet plug in it.

It would appear so, and this...

From here both look 1/2" though.

...would of course make the most sense.

But if the OP is simply not badly mistaken about the size of the male drive stud, wouldn't you agree with me that it's weird?

Instead of going 3/8-inch male to 3/8-inch female or 1/2-inch male to 1/2-inch female, which were the two universal joints typically offered and put into various Craftsman (and other) sets in the mid to late 1940's, it goes from 3/8-inch drive male to 1/2-inch female.

Like an adaptor. Very much like an adaptor, in fact, except it's a universal joint adaptor.

But for what?

You could insert a tool with a 1/2-inch male drive stud (ratchet, hinge handle, etc) into the 1/2-inch drive female opening to drive 3/8-inch drive sockets.

Or, you could insert the 3/8-inch male drive stud into a tool with a 3/8-inch drive female opening (female ratchet, extension, etc) to drive a a tool with a 1/2-inch drive female opening (extension?).

Either way, it's a little odd.

 

[3baygarage]

Yes it would be odd. I can't think of anyone who made a u joint adapter.

 

[four.cycle]

Like an adaptor. Very much like an adaptor, in fact, except it's a universal joint adaptor.

ah so.

it's still awfully odd, but that at least makes sense.

 

[ken w.]

Now I feel stupid for not looking at it closer. It must have been in there awhile as the finish matches perfectly. Thanks for pointing this out.

 

[Private Lugnutz]

No worries, @ken w.

Please confirm that it is inserted into a 1/2-drive square opening. That would still be quite odd regardless of the drive plug.

 

[ken w.]

No worries, @ken w.

Please confirm that it is inserted into a 1/2-drive square opening. That would still be quite odd regardless of the drive plug.

I need to start wearing my reading glasses. This is a 1/2" swivel , with a 1/2" square drive inserted in it. Sorry for the confusion. I'm cleaning out to move and keep finding boxes with unusual things in it.

 

[ken w.]

Pics.

 

[Private Lugnutz]

I need to start wearing my reading glasses. This is a 1/2" swivel , with a 1/2" square drive inserted in it.

Thanks, ken, and again, no worries. We've all been there! I didn't want to pre-suppose that it was probably a service opening that it was jammed in, but that surprises me A LOT less than an adaptor uni joint - and saves a few of the nerdier among us a few hours of furious research.

 

[four.cycle]

yeah.... I've never done anything like that here...