Recommendations for Gearboxes with Keyway Input for Motors Featuring a Keyed Shaft

STEPPERONLINE sells hybrid stepper motors encompassing various sizes from NEMA 6 to NEMA 42. Depending on the size, the type of motor output shaft differs, broadly categorized as follows:

• NEMA 6 - NEMA 24: Round shaft and D-Cut shaft.

• NEMA 34 - NEMA 42: Keyed shaft.

The gearboxes currently available for sale all feature a round input bore:

Considering the shaft-to-bore pairing types, it seems only round shafts and D-Cut shafts can perfectly match the gearbox. So, is a gearbox with a keyway input necessary for motors featuring a keyed shaft?

Actually, it is not required. Our recommendation is to remove the woodruff key, which results in a round shaft. In fact, the vast majority of our customers use this method. You might be concerned about the risk of slipping with this clamping method. This will not occur. Please refer to:

Locking Reliability and Torque Characteristics in Planetary Gearboxes

If you still require a gearbox with a keyway input, please contact us for a custom order. We will machine the gearbox's coupling using a cutting process to adapt it for motors with a keyed shaft.

Updated on: 30/10/2025