Hi

I just noticed the torque spec on your motors. The sheet lists it as 2.4 kg cm. That is the same as 33 inch ounces. Either way it is about half the torque that most of the recommended motors put out. It also is a fairly high inductance motor. That will limit your ability to step it fast, unless you are running high voltage drivers.

Heat wise, a stepper is "good" to about 150 C (the insulation temperature spec ...). That is an internal number. The temperature on the surface will be way below that. It still will be up in the "ouch" 70C range before there is a problem.

Bob