Hook is one of the important parts of crane. It is easy to operate on the wire rope of hoisting mechanism through chain link.
According to the shape, hooks are divided into single and double crane hook.
Single hook: easy to make, easy to use, but limited in force, most used in the working environment with a weight of 80 tons;
Double hook: when the weight is large, the double hook is a better choice, its force is symmetrical, the strength is stronger.
According to the manufacturing method, hooks are divided into forged hooks and Fold type hooks.
Forging hook: forging hook is an integral part of the forging products, straight part is called a hook neck, above the top hook neck thread machining, assembly hook is beams, thrust bearing, such as hook nut of fog.The bending part below is called the hook body.The hook body section is rounded, trapezoid large end, small side outside.The shape of this section can increase the area of pressure of the hook and close the outer edge of the cross section, so that the hook material can be fully utilized.
Fold type hook: fold type hookby several piece of cutting forming plates riveted together, individual crack of plate when the hook won’t destroy, security is good, but the weight is bigger, mostly used in big lifting weight or lifting steel barrels of cranes.The hook is made of high quality carbon steel with good toughness and excellent performance.
According to mechanical properties, there are five levels of work strength: M, P, S, T and V. Adopts DIN, FEM, JIS standard.
M grade with DG20, or DG20Mn
P grade with DG20Mn
S grade with DG34CrMo
T grade below 40t with DG34CrMo, more than 40t with DG34CrNiMo or DG30Cr2Ni2Mo
V grade below 40t with DG34CrNiMo or DG30Cr2Ni2Mo, more than 40t with DG30Cr2Ni2Mo.