Screw is in the daily life of common fasteners, its different can be divided into various types according to the shape of the head, countersunk head screws and cross slot screws are common screws, countersunk head screw on the big small inverted cone, the cross pan head screw head is circular, the two types of screw is not only different shapes, use also has certain gap, the main differences are as follows:

1. The load borne by countersunk head screws in fastening state is larger than that borne by cross pan head screws.

2. Countersunk head screws are often used for fasteners of mechanical parts and mould templates; Pan head screws are usually used to fasten the covers or parts of mechanical cases and housings or household appliances.

3. The top of countersunk head screw is flat; The pan head screw is spherical above.

4, cross slot pan head screw fastening tool is a kind of screw, that is, people often say screwdriver; The tool used for fastening countersunk head screws is an inner hexagon wrench.

5, the section of the head of the pan head screw image semicircle; The cross section image of the countersunk head screw head is a trapezoid.