I'm using an infrared thermometer. The wire gets up to maybe 230º.

Does this thermometer have a fine enough focus for the wire to completely fill its field of view?

 

No. It's the usual red laser dot. On the other hand, the wire remains grey. Not red, and I can put my hand down over it, to within about 3/8" and feel heat, but not enough to bend much of anything. I've seen the same wire doing its job, up to about 350ºF, and it is not grey at that temperature.

 

I've decided to not do any experimenting with the power supply now, with the aim of deciding whether or not to send it back. I may do that anyway, but before I do I need to go over Ohm's Law and learn more about the relationship between resistance, watts, volts, and amps. I know I can make the plastic bender work with a single-setting enclosed power supply and a voltage regulator, so that isn't an issue. My understanding of power supplies is the issue. Thanks to everyone for contributing to this thread. I read all the posts, and this temporary pause is one result of that.

 

No.
The values being numerically equal is a consequence of the nichrome being 1 Ohm. Had it been 2 ohms then you would get 12V at 6A.
Go study and understand ohms law.

Mr. Hall, thanks for including that example in your post. That gives me a place to start in learning more about Ohm's law.

 

I've seen the same wire doing its job, up to about 350ºF, and it is not grey at that temperature.

No.
A domestic oven gets up to that sort of temperature. Have you ever seen the racks in your oven glowing red?
https://en.wikipedia.org/wiki/Red-short_carbon_steel

 

No, can't say I have, but OTOH, they aren't made of NiChrome.