Where are small internal & external square sockets used?

[Zebu Fellenz]

Hi Everyone,

Non-tech here so please excuse what might seem like a stupid question.

I was going through my spare socket drawer and came upon some smaller square sockets, an internal 7/32" and 9/32" (Mac X74, X94) and two external 3/8" and 11/32" (Snap-On PPM412, PPM411A).

Curious what these are used for.

The retiring tech I bought my tools from a few years ago definitely didn't buy unnecessary shiny tools to impress anyone so I'm sure they have a purpose.

My only guess is something brakes related, but I'm really pretty clueless.

Don't tell me they're used for square nuts...

 

[ZRX61]

All over the place on aircraft hydraulics...

 

[customsbyjason]

some of the internal stuff is like drain plugs for transmissions and rear ends

 

[Case]

the external one are used on some lawnmowers and tractors drain plugs along with fill plugs for the differential on a 2000 blazer (just did that required a 3/8 so its off the top of my head)... they're something that make some jobs alot easier then using extensions or the like..

 

[Moose-LandTran]

Crappy French engines and gearboxes. I think some Japanese gearboxes too.

 

[CHRIS LUCKYMAN]

Shifting linkage/couplers on older VW/Porsche.

 

[arizonaadam]

The old guy who put in the vise that came with my house used square bolts.

 

[twincam00]

I know a couple ford transmissions use them for drain/fill plugs, as stated before lawnmowers and other small engines sometimes use these for drain plugs

 

[greasemonkey44]

external squareheads used to be very common with bolts; that faded with the after ww1
some millwrights see alot of these
i still see internal squares on diff or ****** drains
but nothing as small as what you have
was the guy an A&P mechanic

 

[FergusonTO35]

I use them all the time for drain plugs on small engines and equipment. Sometimes you find them on seat bolts of cars too.

 

[KEH]

5/16 square for adjusting brakes on road tractor, according to friend who is a mechanic. I looked out for some for him in the pawnshop, got him a few, he hasen't broken one yet after complaining about them breaking on him. Just goew to show if you have spares you won't break anything.

KEH

 

[GreyOwl]

External used on a lot of older pulleys and your torsion springs for garage doors for set screws.

Charles

 

[TWX]

I have a kit either from a Mac or Matco truck (can't remember) of odd transmission service sockets. I bought them because I needed a 5/16" male square driver to put the plugs into the engine. I now wish that I had just ground down a cheap extension actually, as much as it cost and as little as I've used them.

What really pisses me off is that one of the sockets is 3/8" male square-headed. I don't know why anyone would need that when a socket extension would just fit.

 

[plinker]

What really pisses me off is that one of the sockets is 3/8" male square-headed. I don't know why anyone would need that when a socket extension would just fit.

I've seen some breaker bars and an extension broken/sheared off doing that. I'd rather just use the socket.

I have seen some small internal square plugs on some older diesel engines.

I have used 8 pt sockets quite a bit (mostly on pipe plugs, some square bolts & set screws), but only have two internal plug sockets, a 3/8 & 1/2. Those cover everything Ive needed to do so far.

 

[Sancho]

Most of the bolts on my effluent pump are external square. Im sure thats due it being primarily serviced by plumbers.

 

[Bart Simpson]

Hi Everyone,

Non-tech here so please excuse what might seem like a stupid question.

I was going through my spare socket drawer and came upon some smaller square sockets, an internal 7/32" and 9/32" (Mac X74, X94) and two external 3/8" and 11/32" (Snap-On PPM412, PPM411A).

Curious what these are used for.

The retiring tech I bought my tools from a few years ago definitely didn't buy unnecessary shiny tools to impress anyone so I'm sure they have a purpose.

My only guess is something brakes related, but I'm really pretty clueless.

Don't tell me they're used for square nuts...

What you have are internal and external pipe plug sockets.
These are used on all kinds of equipment where there is a fluid.

In the Snap On part #'s you referenced the PPM stands for pipe plug male, the last 2 numbers are the size in 32nds.

No they are not made for use on square nuts but you could use them for that.
8 point sockets are generally used for square nuts and bolts but again you could also use those for pipe plugs as well.

 

[Dust]

Spare tire carriers that need to be rotated to lower the spare. Sadly a 1/2" is too big, but a 7/16" is too small. I have yet to find a metric sized square or 8pt socket, though I haven't been looking very hard.