If you need a corrosion-resistant motor with powerful force, this 1.8 degree size 42 hybrid DC stepping motor could be for you. It is totally enclosed with permanently lubricated ball bearings. The bi-directional size 42 has holding torque up to 2100 oz-in with a step angle accuracy of ±3% non-cumulative.
ElectroCraft TP42 STEPPER MOTOR
Size Nema 42, 1.8° Holding Torque up to 2100 oz-in or 1482.81 Ncm Speed up to 24 RPS