The 1.0.5 mm diameter steel wire is heated evenly in a furnace until reddish, and then gradually cooled. After cooling, wrap it around a 15mm diameter round iron holder, about 40mm in length. Then put the stove to red. Then put it in cold water or oil to quench it to form a spring.

2. Take the wooden floor of 310×80×5mm and nail a grove of 80×15×5mm at the top. A sheep's eye rim installed in the center of the small wooden boat with the ring. After soldering, put the other end of the wire with a diameter of 2.5mm and a length of 150mm on the ring. The lower end of the wire hook, the upper spring is welded, and then a thin iron plate is installed as the pointer. The pointer should be a vertical line, the position of which can be adjusted. The top of the small wire frame back plate is bent into a semi-circular frame with iron hooks to prevent the iron hooks from shaking.

3. A piece of white paper sticks to the span of the floor. The pointer is not set to the range where the weight on the hook is set to zero, then open the hook and hang 1.0N, 2.0N, 3.0N, 4.0N, 5.0N and other hook codes, each hook code is aligned with the pointer and drawn on the range , the interval between the ranges, and then make the appropriate aliquots. This completes the spring dynamometer.