Some technical knowledge about screwdriver
A metal rod runs through the handle of the perforated cross screwdriver. This is a strong construction, because the knife is integrated with the handle, and the perforated steel rod runs through the back of the handle. In this way, the hammer can be used to hit the back of the knife without damaging the screwdriver. Screwdriver manufacturer reminds you, the disadvantage is that this kind of tool can not be used for the operation of electrical equipment, even if the switch is pulled out also not, the price is a little more expensive.
Turn the screwdriver is a kind of used to twist screws to force the tools in place, usually with a thin wedge head, can insert the slotted screw head or notch in beijing-tianjin-hebei JinYu and shaanxi dialect is called "screwdriver", anhui and hubei and other places known as the "driver", the central and western regions known as the "change knife", Yangtze river delta region known as the "screw driver. There are two main characters (negative) and cross (positive). Common still have hexagon screwdriver, include inside hexagon and outside hexagon two kinds.
When the screwdriver was used to pry the paint cover, the lever worked. The greater the distance from the power point to the fulcrum, the more labor saving, so the long screwdriver is more labor saving than the short screwdriver.
A screwdriver China USES the working principle of a wheel shaft when it is used to turn a screw. The larger the wheel, the less effort it takes to turn the screw, so using a screwdriver with a thick handle is more labor-saving than using a screwdriver with a thin handle.