What do you do when it is Saturday afternoon the local hardware store closed at noon and you are right in the middle of wanting to run some 1" emt conduit when you run out of box connectors?
Well you can drop everything and drive 75 miles 1 way to the next open store then by the time you get back you are either out of time or out of the mood plus you spent $20.00 on diesel just for half a dozen connectors.
Or you do like I did you go to your pile of usable stock and someday materials dig out several cut off pieces of 1" pipe that already had threads on one end cut off what you need and bore them half way through to make your own box to EMT connectors
1" pipe is the same thing as what is called 1" ridged conduit. the threads are the same as well. you just need to bore it out large enough for the EMT to slip in this works for 1/2, 3/4, 1 1/4" 1 1/2" 2" and so on Only when getting above 1 1/2" the shell thickness may be thinner. I haven't ever had the occasion to try anything larger than 2"
My fit was almost a tap in fit and the conduit is going between 2 boxes so I really didn't need the locking screw but put in in anyway by making a weld glob then drilling and taping to 10-24