Okay, "knowing" what I need with a 250EX, I have a good idea, seemingly now,

[performance]

Rambozo,
There are TWO ratings on a torch, AC and DC. The 20 is only 250 amps DC current. AC, on ours, and several others is only 175 amps. That's why. The AC rating on the WP 18 is 250 amps. DC 350.

26 is 250 amps DC, 160 amps AC. 17 is 150 amps DC, 120amps AC. 9 is 125DC, 80 AC (with a lesser 60% duty cycle...others are at 100%.)