My father, Bud, my mentor and best friend ever (after I became a father and finally grokked the Old Man) would look at all of this and throw the bullshit flag. He was an electrician for 50 years and believed in using the best components from a rational POV.
I learned a lot from my Dad.
Buy the best tools and save up for them if necessary.
Tighten it, wait 5 minutes and tighten it again. He taught me about cold flow.
NEVER do anything stupid with 250.. You "might" get away on 120, but don't press your luck.
With 220-250, put your left hand in your pocket or an insulated glove. The left arm is right next to the heart's natural pacemaker.
Make sure every connecting surface is as clean as you can get it. Clean it, wash it, clean it again.
Be particularly careful with DC, especially when a battery is involved. He almost lost his ring finger when he reached under the dashboard of a '48 Chevy he was rodding. Shorted at the radio power input. It was REALLY ugly afterwards for the remainder of his life.
He worked the last 20 years of his profession as the chief electrician and head of maintenance at the reactor at Sandia National Labs.
Even so, I can say that he would not believe that proper cables, greater current capacity, connectors or any of the things we take for granted as true.
I wish I could have showed him
. It would have stoked a fire in the Oldster's brain pan.
Miss you, Pop. We'll talk, later