The store bought hinged metal dohickeys for marking a square cut or a saddle cut on the end of a pipe cost about $16-$20 for each size pipe. Around here weldors use a cutting torch to cut the shape after marking the pipe with soapstone or...
I am so poor with a torch that this is a joke for me. I have tried and for me practice does NOT make perfect, practice makes frustration as I spoil more and more material.
Some folks use a jig on their drill press with hole saws. this works really good FOR THIN WALL TUBING. Heavy wall 2 3/8 pipe takes a long time to cut with a hole saw and you don't get so many cuts per blade.
I have a hydraulic press. I flatten the ends of the heavy wall tubing and can weld the flattened end to another pipe pretty easily. The thick walled pipe tends to crack where the radius of curvature is smallest when smashing them flat but when welding the joint I just make a quick pass over the crack and there is no problem.
I use this technique for welding "H" braces and corner fixtures for fences. Most of the stress on the joints is either compression or tension without much torsion or bending so the fact that this technique yields a weaker joint is of no concern whatsoever.
I have used this method to attach three pipes together in a compound triangle configuration with good success where a fish mouth or saddle would not have worked. Maybe one day someone will show me how to use a torch to cut a decent saddle. Until that skill is mastered, smashing the ends flat is working just fine.
I built a "gate brace" (see attachment). The gate brace as built is the "not darkened in) pipe. Wire tension of 5 strands of barbed wire puling in opposite directions bowed the vertical pipes. they are set in concrete and are burried over 3 ft in ground.
I pulled them back in shape with a "come along" and added the pipes depicted as darkened in. All joints in this fixture, original and added, are smashed pipe with no fishmouths (saddles). Looks OK works great.
I consider this technique " A Smashing Success" and if I didn't have a hydraulic press, I'd use my anvil and a sledge. My neighbor to the south has been helping me with our common fences and gates and also is no artist with a torch. He uses what he calls "gap rod" (steel scraps) to fill the ugly gaps in his saddle cuts while welding. His saddles are so poor he bought square tubing at considerable expense to build gates so he wouldn't have to cut saddles. He loves the results I got smashing the ends flat instead.
Maybe a cuting torch proof refractory material could be formed in the shape of a saddle and made to slip over the pipe to be saddle cut. Maybe then us ignorant savages could cut a decent saddle. Of course , now that asbestos is not used, what shoulld it be made of?
Hope this encourages the less skilled among us to fabricate with pipe even though they aren't an artiste with a cutting torch.
Pat