kWm

kWm stands for kilowatt-mechanical, a usage note found in some engineering contexts to denote mechanical power. It is used to distinguish shaft power delivered by a machine (such as an engine or turbine) from electrical power measured or consumed, which is often labeled as kWe or kW_e. The term is not an official SI unit designation, but a conventional abbreviation still encountered in catalogs, technical datasheets, and rotor or engine specifications.

In practical terms, 1 kWm equals 1000 watts of mechanical power. When converting power to common horsepower units, 1 kWm is approximately 1.341 mechanical horsepower (hp). In many applications, especially in automotive and industrial settings, kWm is used to specify the shaft power that the machine can deliver, before accounting for losses in drivetrains, transmissions, or electrical conversion.

Measurement and relationships: mechanical power can be calculated from torque and rotational speed using P = τ × ω, where P is power, τ is torque, and ω is angular velocity. A rating expressed as kWm typically implies the output at the shaft, whereas electrical ratings (kWe or kW_e) refer to electrical input or output, depending on the context. For engines and turbines, distinguishing mechanical power (kWm) from electrical power is important for assessing efficiency, performance, and system losses.

Summary: kWm is a conventional label used to indicate mechanical, shaft-delivered power in kilowatts. While widely understood in some engineering circles, it is not a strict SI designation, with the more common practice being to specify power in kW and clearly state whether it is mechanical or electrical.