Mainline tool Coupler Nuts

[K.I. Joe]

I am making a mainline tool and was wondering what size threaded rod coupler nut you used on your for Tubing from 3/4 to 1.5 Inches. Thanks

[mellondome]

Use pipe collar of same size.

[maple flats]

Off hand I'm not sure, but I have a 1.25-1.5" mainline tool with 2 sets of bolt in adapters to handle 3/4" and 1". In each case the clamps are made from pipe threaded couplers and not threaded rod, unlike the 5/16 tools. For the adapters, there is a single hole in the 1.5" welded in half couplers (actually a little less than half) and the adapters each have a length of threaded rod welded to the back side. Then to adapt, I simply bolt in the 3/4 or 1" adapters into the 1.5" clamps and then I use it on that size. I find this especially handy if I'm pressing for example a 3/4" to a 1", it then is a straight push, however, if I join a 1.25" to a 1" (or 1.5" for that matter) the push is offset because only the 1.5" has the holes to bolt in the other sizes. I suppose I could drill a hole in the 1.25" clamps too and then I'd have every combo covered except 1.25 to 1.5".
I think the 3/4" adapters may have been customized because it has 2 layers, the smaller welded into the next size larger, it also looks like they likely turned the threads to remove part of them on the outer layer before welding in the inner layer to fit. Sometime when I'm at the sugarhouse I'll try to remember to determine the actual pipe coupling sizes. I think on each size the sharp part of the threads have been removed some.