Chinese Steelyard Balance Scale

The steelyard balance scale is a Chinese invention. As early as 200 B.C., China began to make a scale of this type big enough to weigh several hundred pounds.

The steelyard consisted of the following parts: an arm, a hook, lifting cords and a weight. The arm or beam measured about 1.5 metres long, graduated with the weight units 'Jin' (斤) and 'Liang' (两). The hook, hanging from one end of the arm, was used to lift up the object to be weighed. Hanging from the other part of the arm was the free moving weight, attached on a looped string. On the arm was fixed one, two or three lifting cords, placed much closer to the hook than to the other end. Anything to be weighed should be picked up by the hook, while the weigher lifted up the whole steelyard, holding one of the cords. The weight, then will be slided left or right until a perfect balance of the beam found. Then the weight from the graduation mark on which the weight-string rested will be read.

This kind of steelyard is still in widespread use at market gatherings in China. They may be made in varying sizes working by the same principle, with the large ones to weigh food grain in bulk, pigs or sheep or their carcasses, and medium-sized ones for smaller transactions. There is also a miniature steelyard only about one third of a metre (about 1 foot) long, graduated with 'Liang' (两) and 'Qian' (钱), used to weigh medicinal herbs and sliver or gold. It first appeared about 1,000 years ago.

The steelyard is more convenient than the platform scale. Not only can it be carried around easily, but there is also no need for a whole set of weights. Corresponding to the lifting cords are different sets of graduation marks on the arm for different measuring ranges.

Pictures below are the two Chinese steelyard balance scales from my collection.

Chinese steelyard balance scales.

The hook of the Chinese steelyard balance scale.

The hook of the Chinese steelyard balance scale.

Two different weights.