1. The level of lifting chain:
When buying cranes regularly, you will hear that the manufacturer introduces the lifting chain as the 80 level professional chain, and the lifting chain actually has 3 levels.
High strength class I 80: in the 80 stage lifting chain rigging, the high-strength type I system is the most widely used.
High strength type II 80: this type of application is not as wide as type I, and the same chain diameter and rated load chain can be linked to the parts.
Super strong type 100: compared with the 80 stage lifting chain, the biggest advantage of this level is the same diameter, the rated load is 25% higher, the surface has higher hardness and better toughness; in addition, the surface color is different from the 80 grade chain, and the chain and its structural components are green.
2. The forging standard of the lifting chain:
The lifting chain level of the hand hoist should be in accordance with the regulations of the industry standard GB4829 and GB5802. The design and manufacture of the short ring chain of its components should be in accordance with the provisions of the GB4829. The material should be composed of the calming steel produced by the flat furnace, the electric furnace or the oxygen top blown converter. The steel should have good cold bending, weldability and not easy to produce strain aging and brittleness.
3. Breaking force and total ultimate elongation of lifting chain.
The breaking load of hoist chain is related to the safety in operation, and its determination should also be stipulated in the GB4829 standard.
Usually the breaking load of high quality product lifting chain should be more than 4 times of rated working load. The chain should be pulled at 2.5 times the rated load.