Use Precautions and Scrap Standard of Hook

Types of Hook

Hooks can be Forged hooks and plate hooks depending on differences in manufacturing methods.

Forged Hook Usually adopts No.20 high quality carbon steel which is forged, pressed, annealed and then machined. Forged hooks can be made into single and double hooks.

Plate hook is generally used to lift heavy lifting machinery. The plate hook is made of a 30mm thick formed plate overlapping pin. The plate hook is equipped with a guard plate, generally made of Q235A, Q235B or 16mn steel rolled steel plate. Plate hook is also divided into single hook and double hook, single hook is mainly used for casting crane.

Hook section shapes include rectangle, trapezoid and T shape. Cranes usually use trapezoidal cross section of single hook or double hook; Rectangular section is generally plate hook; Electric hoist usually adopts T - shaped section hook. There is a certain relationship between the main dimensions of Hook, for example, between opening degree S and hook hole diameter D, S=0.75D.

Hook Safety precautions

Hooks shall be produced by regular professional manufacturers in accordance with Hook technical conditions and safety specifications, and the products shall have the manufacturer's quality certificate, otherwise they shall not be used.

The new hook shall carry out load test and be used only after it is qualified. The opening of the measured hook shall not exceed 0.25% of the original opening.

Hooks should be regularly checked for cracks or severe deformation, corrosion and wear during use.

Hooks should be tested annually. During the test, the static test was carried out for 10min at 1.25 times the allowable working load, and then checked for cracks, notches and residual deformation with a magnifying glass or other methods.

Dangerous sections should be cleaned with kerosene and checked for cracks with a magnifying glass. Plate hooks should be checked for bushing and dowel wear.

The Hook shall not be repaired if there are defects.

Hook scrap standard

When one of the following situations occurs, it shall be scrapped and shall not be repaired.

When there are cracks in the surface.

When the dangerous section wear reaches 10% of the original size.

When the torsion deformation exceeds 10 degrees.

When the dangerous section and Hook neck produce plastic deformation.

When the plate hook bushing wear reaches 50% of the original size, the bushing should be scrapped; When the wear of the pin exceeds the nominal diameter of 3%~5% should be renewed.

When the wear of the mandrel of the plate hook reaches 5% of the original size, the mandrel should be scrapped and updated.

When the opening is 15% larger than the original size.

To do a good job in the safe use and management of construction equipment is an effective way to ensure the safety of individuals and enterprises in production. All construction units should strictly control the use procedures and scrap time of equipment, and do not endanger others and enterprises due to temporary negligence.