If you're looking to speed up the assembly process and don't want to weld the 1/2" pipe threading die that comes with the Harbor Freight pipe threader kit to the tube roller drive axle, we now sell a fully machined drive hub that will allow you to easily attach the pipe threader to the drive axle. The 1/2" pipe threading die is not sold individually through Harbor Freight so once it is welded in place you are not able to take it off if/when you need to use the tool as it was originally intended for. We also sell the tubing roller drive axle that is machined out of 4130 chromoly steel.
The machined drive hub will need to be tack welded to the drive axle, as set screws and/or key ways have a tendency to come loose under the high torque loads and the constant back and forth motion of the pipe threader. This machined hub will fit both the HULK tube roller as well as the Harbor Freight tube roller.