K Series vs S Series Gearbox

K and S are both right-angle families, but they use different transmission architectures. K uses a helical-bevel layout and extends into a much higher reference torque range. S combines a helical stage with a worm stage and is often considered for compact small- and medium-power right-angle applications.

Quick technical comparison

K Series

S Series

What should decide the selection?

1. Shaft arrangement

Choose the family that naturally fits the machine geometry. Avoid adding couplings or transfer shafts only to force an unsuitable gearbox layout.

2. Required output speed and ratio

Calculate the target ratio from actual input speed and process output speed. Then confirm the ratio exists in a valid performance row for the selected size.

3. Output torque and duty

Compare continuous duty, service factor, shock loading and external shaft loads. A larger reference maximum torque does not mean every configuration can operate continuously at that value.

4. Output and mounting interface

Solid shaft, hollow shaft, flange and shrink-disc arrangements can change replacement compatibility even when the base size is similar.

5. Maintenance and installation

Mounting position affects lubrication. Replacement work also requires dimensional confirmation against the existing machine.

Selection rule of thumb

Use the comparison to choose the gearbox family, then use the series selection table to choose the configuration.