Pipe plug size
#1
#2
#3
If it is a recessed square type, try a 3/8" ratchet or extension, if that is to small, just take a junk 1/2" square drive extension and grind it to fit, if too large, take a junk 3/8" square drive extension and grind it to fit.
Or if you have pieces of square bar or keystock laying around, find a piece that fits and use that with an adjustable wrench.
If it is a standard square head plug and it is hard to get at with a wrench, just find a 12 point socket that fits it good and use it.
If you like to accumulate tools, Grey Pneumatic tools has sets of sockets for square recess and square pipe plugs. Not too expensive.
Or if you have pieces of square bar or keystock laying around, find a piece that fits and use that with an adjustable wrench.
If it is a standard square head plug and it is hard to get at with a wrench, just find a 12 point socket that fits it good and use it.
If you like to accumulate tools, Grey Pneumatic tools has sets of sockets for square recess and square pipe plugs. Not too expensive.
#4
#6