Characteristic Differences Between Large Tonnage Crane Hooks and Ordinary Crane Hooks

Crane hook is a very critical component in lifting machinery, usually classified according to the materials used, manufacturing process, use and other factors.

Different types of crane hooks may have different shapes, manufacturing processes, operating methods or other characteristics. Different types of crane hooks are usually capable of meeting different usage needs, load ratings, size and category requirements.

You can click this link to learn more crane hook type classification:

https://www.glorycranerail.com/use-manufacture-and-classification-of-hook-groups/

Hooks are configured and purchased with the crane, different manufacturers, different tonnages of hooks are generally different, roughly divided into the following forms:

1. Ball hook (small tonnage, less than 20 tonnes)

2. Single hook (commonly used, less than 100 tonnes)

3. Double hook (large tonnage, more than 100 tonnes)

4. Specialised hooks (oversized hooks)

The following matters should be noted when the hook is selected:

(1) The rated load of the hook should be greater than the lifting weight.

(2) The size of the hook should meet the requirements of lanyard connection to ensure that the rope is not pressed.

(3) The weight of hooks of the same tonnage with different crane configurations has a large difference and should be verified according to the crane manufacturer’s manual when calculating the weight to be lifted.

(4) Whether the rated load of the crane contains the weight of the hook should be checked according to the manual. The rated weight of the crane of general tonnage has already taken into account the weight of the hook, while the rated weight of the crane of large tonnage does not contain the weight of the hook, and it should be calculated separately such as the weight of the lifting load.

Large Hooks

Large hooks of more than 50t can only be produced by a few companies in China, and the key index in its production is the mechanical properties. The tonnage of single hook is 50-100t, the material is 16Mn or 20# steel; the tonnage of double hook is 160-200t, the material is 20MnMo or 20MnMonb.

Large tonnage crane hook is a bridge crane commonly used pickup device, is one of the three important components of its safe production (brake, wire rope, hook), if not used properly, it is very easy to be damaged or broken, resulting in major accidents and accidents, it is necessary to lifting hooks to carry out regular inspections, found that the problem, and deal with it in a timely manner.

Large hook manufacturing materials

Hooks are made from ingots by forging, whether single hook type or double hook type, the stage of forging are through the material → upsetting, pulling the length of each sequence. At this stage, in addition to forging the internal cast defects, the cast dendritic organisation will also be broken up and the grain is refined. In addition, through the stage of forging can also make the billet formation of high toughness and strength of the continuity of the fibre band, the direction of the fibre and the hook structure in the same direction. The formation of the fibre band has an important role and influence on the performance of the hook.

In the second stage of forging, the single hook will be formed by direct simmering, with no change in the direction of the fibres within it.The double hooks will continue to be forged in the hook head part, and will be formed by gas cutting and then finished by die forging to achieve the finished shape, and its internal fibre tissue is in secondary continuity.

Large hook performance chemical treatment

Due to the hook in the forging process to be heated to 1250 ℃, and often in the local forging state, and thus its rod often produce coarse grain phenomenon. In order to ensure that the mechanical properties of the hook index, it is necessary to use appropriate heat treatment process of coarse grains in the rod.

Unique features of large tonnage crane hook

1. Large tonnage lifting hook is an important lifting part in lifting machinery, its material is generally used 20 steel or 16n steel.

2. Large tonnage lifting hooks are mostly made of M and P strength grade to ensure good rigidity and hardness.

3. Moulded forging with ear shank threaded shank single hook structure form.

4. Large tonnage lifting hook hook body (most) cross-section is rounded trapezoid, the inner side of the big side, so as to increase the area to withstand the pressure of the ring or rope, so that the cross-section of the outer edge of the strength of the close to equal, not only the rational use of materials, but also to reduce the weight of the hook.

5. large tonnage lifting hook material selection of anti-magnetic steel, solid fusion after die forging, hardness of 180HB, with high mechanical strength and impact toughness, in the ability to withstand the winch lifting mechanism of the starting and braking process of the impact load.

Glory Rail is based on rail systems. At the same time, we expanded the research, development, and production of crane hooks. Provide different types of lifting hook products for various cranes and port machinery equipment.