A lifting hook is a mechanism used for grabbing and lifting loads or objects through the use of a machine such as a crane or a hoist.
There are many different kinds of hooks used for lifting, they are designed specifically to carry certain loads. Some are designed only for chain slings whilst some are more general and can be used for both chain and webbing.
The hooks are attached to lifting chains through an eye hole but may have a swivel or clevis to allow for rotation or positioning of the hook under load.
A hook is made up of 6 main components. These are the Eye, Shank, Throat, Bowl, Point and Safety latch. These components allow the hook to support adequate weight and lift heavy loads with minimal failure.
As hooks are under constant…show more content… - Hardness is also necessary to prevent the hook from being dented and to ensure wear is minimal.
Hardness testing is generally non destructive but some tests can leave a dent in the hook such as Rockwell, Brinell and Vickers. For toughness testing we generally use the Charpy and Izod test. S
Rockwell Hardness test – The Rockwell hardness test is the most commonly used form of hardness test for metallic and polymer materials. Although it doesn’t tell us the direct measurement of any performance properties, the hardness of a material does directly correlate with strength, wear resistance and other properties. The Rockwell test is an indentation testing method, it involves either a conical diamond or a hard steel metal ball.
It begins with the indentor being set into the material at a ‘minor load’, a major load is then applied ontop of the minor load and is held for a set time period. The force on the indentor is then decreased back to minor load and the Rockwell hardness number is then calculated from the depth of permament deformation. This test can be done fully automatically, making it popular in