Tonarmsvikt

Tonarmsvikt is a term used in Swedish technical literature to denote the weight of a mechanical arm or crane arm, expressed in metric ton units. It refers to the mass of the arm itself, distinct from the payload the arm is designed to lift. The word is formed from ton (metric ton), arm, and vikt (weight). In engineering practice, tonarmsvikt is considered as part of the system mass that loads the base, joints, and drive mechanisms, influencing stability, dynamic response, and required safety factors.

The quantity is obtained by measuring or calculating the arm’s mass and converting to metric tons by dividing by 1000; when the mass is distributed, the gravitational force is still related to the total mass, though it is often described in tonnage for planning purposes. For a uniform arm, tonarmsvikt equals the mass in kilograms divided by 1000; for multi-segment arms, the total tonarmsvikt is the sum of segment masses, with attention to the overall center of gravity.

In design practice, tonarmsvikt is used together with payload characteristics to assess total load, tipping moments, and control requirements. For example, a robotic arm with a mass of 250 kg has a tonarmsvikt of 0.25 tons, which contributes to base, support, and track loads during operation.

Related concepts include payload, load moment, center of gravity, mass distribution, and safety standards for lifting equipment.