Facts about Tools

Most tools are ancient objects that existed in the 1000's of years. The hammer and plain are said to have been invented by the Romans, while the saw and the set-square of the Egyptians. The screwdriver can be traced to the 1400s. Screws were expensive, spikes were cheap, so screwdrivers were an exclusive item. Demand increased, but the screwdriver in its basic form was quite similar.

A wrench you use to tighten or loosen nuts or bolts. A stepless variation, which can be used for nuts and bolts of varying sizes, called adjustable spanner/wrench.

With a torque wrench you can tighten nuts and bolts to a specified torque for accurate assembly work. It is usually in the form of a socket wrench with special internal mechanisms. It was invented by Conrad Bahr in 1918 while working for the New York City Water Department. It was designed to prevent the tightened bolts on the water pipes and steam pipes from coming loose.

Function of Torque Wrench
With a torque wrench you have to pull your hand properly positioned on the handle. You should tighten calmly and steadily, pulling until a "click" sound is heard. If the setting is spring-loaded, always set the tool to "0" after work. One may lose accuracy if the spring is overloaded.