What kind of material is good for screw driver?
When the screw head opening bald slip can use hammer screwdriver to screw the tick groove deep, easy to screw, the screwdriver to unscathed; screwdriver is often used to pry things, requires a certain toughness without bending will not break. In general, I hope the head of the screwdriver is more than HRC60 in hardness, and it is not easy to rust.
The head of a quality screwdriver is made of spring steel of relatively high hardness. A good screwdriver should be hard and not crisp, tough and tough.
The screwdriver does not have a round head because the round head has no torque at all. One word is to make sure that there is torque, and the cross allows the force to be distributed more evenly. According to the power source, there are manual screwdriver and electric screwdriver. According to the batch head or cutter head, there is a word (flat, head) and cross (Phillips)
