Review on Efficient Stepper Motor with 4-Wire Shaft for Router Applications by Larry Boyd

These are the stepper motors I use in most automation projects. Good torque for this size. Make sure the driver is tall enough. A 2 amp driver will not help. The mounting holes are blank to allow a screw to pass through, but are the ideal diameter for a 1/4-20 faucet if you need to install it. I've used them both ways with no problems.