steelyards

A steelyard is a portable balance used for weighing heavy goods. It consists of a rigid beam with two unequal arms supported at a fulcrum. A hook or pan is attached to the short arm for the load, while a sliding counterweight moves along the longer arm. When the system is balanced, the position of the counterweight on the long arm provides the readable measure of the load, via a calibrated scale. The lever principle ensures that a relatively small counterweight can balance a much heavier object, with the weight read from the counterweight’s position.

Operation and calibration: The item to be weighed is hung from the hook at the short arm. The sliding weight is moved along the long arm until the beam is horizontal. The scale on the long arm is marked with weight values so that the reading corresponds to the force of the load, taking into account the ratio of the arm lengths (the short arm length divided by the long arm length).

History and use: Steelyards have ancient origins and have been used in many cultures worldwide. They were popular in markets, mills, mines, and trading posts to weigh grains, metals, textiles, and other bulk goods. Their portability and simple construction made them a common tool before reliable standardized weights and modern scales.

Construction and variations: Early steelyards were made from wood with iron fittings; later versions used brass or steel. The longer, graduated arm may be straight or curved, sometimes with a lock or pin to fix readings. Some designs include multiple scales for different units or densities.

Modern status: In most countries steelyards have been largely superseded by calibrated scales and electronic balances, but they remain of interest for historical study and in some traditional markets or educational settings.