How often should Lifting Chains be Tested?

The lifting chain should be cleaned regularly after using for a period of time. During the cleaning process, the lifting chain should not be damaged. The characteristics should be careful not to use corrosive liquid to make the chain hydrogen brittle during the cleaning process. The temperature of the lifting chain is too high, and the metal elements of the chain alloy should not be precipitated or diffused.

Check the lifting chain to ensure that the light is bright enough, and each chain should be inspected, focusing on deformation, scratches, corrosion, and inner ring wear.

A wear check of the contact points of the hoisting chain can loosen the chain. If the wear is found to be severe, the tool can be used for measurement. One is to select a chain that is not used and worn to stretch; the other is to make the chain into a natural vertical state; the third is to measure the data of the worn chain and the unworn chain pitch, and calculate the average chain after wear. The proportion of the chain link increase.

Testing requirements

1. The length of the chain

The wear of the chain pin and the chain and the elongation of the chain increase the chain length, and the increase is the result of two factors of wear and elongation.

2. The wear value of the chain

As the center of the load deviates from the center of the spreader, the chain is tilted, the chains are rubbed together, the wear is thinned, and the load bearing capacity is reduced, especially in the vicinity of the sprocket.

3. Wear of the edge of the chain

The chain rolls on the sprocket, and the friction between the chain and the sprocket causes the edge of the chain to wear more narrowly.

Visual inspection

1. First check whether the lifting chain has deformation, fine cracks, rust marks, etc. The qualified lifting chain does not have any defects affecting the operation.

2, inspection of the manufacturing details, we can check from the mouth of the welding mouth, the mouth of the package protrudes a circle than the chain, and when the touch, the chain is smooth, no burrs, no scratches, etc., is a good quality chain.

3. No abnormal sound or vibration is generated during use.

4. The lifting chain selected for good quality hoists are made of high quality alloy steel, while some small manufacturers or informal enterprises have rough workmanship or simple materials, and some deviations will occur in the production chain. 

Chain retirement judgment

1. The allowable wear value of the chain shall not exceed 10% of the diameter of the ring chain or the thickness of the accessory;

2. From the plane where the main ring is not bent, the main ring is distorted by more than 10 degrees and should be scrapped;

3. Cracks appearing in any part of the chain, bending or twisting phenomenon and stuck or deadlock between the ring hinges are prohibited and cannot be excluded;

4. The permanent elongation of the chain and single ring shall not exceed 5% of the original length.