Will these steppers work for the mpcnc with A4988 drivers.
Yes. They are near the edge of the posted requirements, and you won’t necessarily get blazing speed out of them, but if you’re just cutting wood on a reasonably sized machine, you should be fine.
I would like to cut metals like brass and aluminum.
What about these?
For best performance, either get them from Ryan, or look at this:
Smaller motors have both lower torque and lower maximum current. Even if you only use 1.5A and 45 Ncm (perhaps limited by the stepper driver), the larger motor will stay cooler, so less chance of warping the plastic parts. There is very little difference in cost, so there is no real disadvantage to using the larger recommended motors.