Daily maintenance and care methods for crane hooks
The crane hook is the core load-bearing component of the lifting equipment. Its safety is directly related to the safety of personnel and equipment. To ensure that the hook is always in good condition, the maintenance and replacement standards must be strictly implemented. The following is a detailed maintenance inspection process, replacement standards and operating specifications.
1. Hook maintenance inspection process
1. Daily inspection (before each use)
-
Visual inspection :
-
Check the hook surface for cracks, deformation or severe rust.
-
Verify that anti-unhooking devices (such as spring locks) are intact and functioning properly.
-
-
Flexibility Check :
-
The hook should be able to rotate freely without sticking.
-
Check whether the bearings or pins are well lubricated.
-
-
Logo inspection :
-
Confirm that the rated load marking on the hook is clearly visible and not worn or altered.
-
2. Monthly inspection
-
Non-destructive testing (NDT) :
-
Magnetic particle testing (MT) : Detect surface cracks (especially hook neck and threaded areas).
-
Ultrasonic testing (UT) : Detect internal defects (such as slag inclusions, pores).
-
-
Size Measurements :
-
Use a caliper to measure the wear on the hook (if it exceeds 10% of the original size, it needs to be replaced).
-
Check for thread wear (for removable hooks).
-
3. Annual comprehensive inspection
-
Load test :
-
Conduct a static load test of 1.25 times the rated load (hanging for 10 minutes, no permanent deformation).
-
-
Rotating mechanism maintenance :
-
Disassemble and clean the bearing, and replace the grease (high temperature extreme pressure grease is recommended).
-
-
Third-party testing :
-
A test report shall be issued by a qualified organization (such as one that complies with GB/T 10051.1 standard).
-
2. Hook Replacement Standard
1. Compulsory scrapping conditions
If any of the following conditions occur, the hook must be replaced immediately:
-
Cracks : Visible cracks (even tiny) in any part.
-
Deformation :
-
The hook body is bent and deformed by more than 10°.
-
The hook width is worn more than 10% of the original size.
-
-
Thread damage : The threads used for connection are stripped, broken or severely worn.
-
Corrosion : The rust depth exceeds 5% of the original thickness (affecting the structural strength).
2. Recommended replacement cycle
| Usage Environment | Recommended replacement cycle | Remark |
|---|---|---|
| Normal working conditions (indoor) | 5~8 years | Regular check-ups without abnormalities can extend the |
| High frequency use (port) | 3-5 years | UT/MT testing every 2 years |
| Harsh environment (chemical) | 2~3 years | Additional monitoring of corrosion rates is required |
3. Hook replacement operation specifications
1. Preparation before replacement
-
Shutdown and power off : Make sure the power to the crane is turned off and hang a "No Operation" warning sign.
-
Load unloading : Remove all loads from the hook and place in a safe area.
-
Tool preparation :
-
Torque wrench (for threaded hook connections).
-
Hydraulic jack (heavy duty hook removal aid).
-
Wire rope cutter (if sling replacement is required).
-
2. Remove the old hook
-
To release the connection :
-
Use a torque wrench to remove the nut/pin (be sure to save the lock washer).
-
-
Check the mating surfaces :
-
Clean any rust or burrs on the mounting surface to ensure that the new hook fits tightly.
-
-
Recording issues :
-
Take photos of the damaged parts of the old hook and archive them for subsequent analysis.
-
3. Install new hook
-
Check specifications :
-
Confirm that the rated load and material of the new hook are consistent with those of the old hook (refer to GB/T 10051.1).
-
-
Lubrication and assembly :
-
Apply high-temperature grease (such as molybdenum disulfide) to threads and bearings.
-
Use a torque wrench to tighten according to the standard (e.g. M36 bolts require 1200 N·m torque).
-
-
Functional testing :
-
The rotational flexibility and anti-unhooking device are tested without load.
-
Carry out a 1.1 times dynamic load test (lifting/lowering 3 times).
-
4. Maintenance and replacement precautions
1. Safety Warning
-
Welding repair is prohibited : welding is not allowed after cracks appear on the hook, and it must be replaced.
-
Overloading is strictly prohibited : even if the appearance is intact, exceeding the rated load will be considered a violation.
-
Personnel training : Maintenance personnel must hold a special equipment operation certificate (such as Q3).
2. Spare parts management
-
Procurement channels : Choose suppliers with ISO 9001 certification and ask for material reports.
-
Inventory strategy :
-
Always have 1 to 2 hooks of the same model available (especially in high-frequency usage situations).
-
Old hooks must be destroyed after being scrapped (to prevent misuse).
-
3. Documentation
-
Maintenance log : record the date of each inspection, problems found and treatment measures.
-
Replacement report : includes the serial number of the new hook, test data and operator's signature.
V. Typical Case Analysis
Case 1: Hook thread slipping accident
-
Phenomenon : The hook in a workshop suddenly fell off when lifting 10t of cargo.
-
Cause : The threads were not lubricated for a long time, resulting in wear and tear, and were not replaced in time.
-
Lesson : Thread condition must be checked monthly and lock nuts must be used.
Case 2: Hook wear exceeds limit
-
Phenomenon : The width of the port hook was worn from 50mm to 58mm (the standard limit is 55mm).
-
Consequences : The sling came off and damaged the equipment.
-
Improvement : Install a hook wear scale to achieve visual monitoring.
VI. Conclusion
-
Prevention is better than emergency repair : discover hidden dangers in advance through regular inspections (daily inspection + monthly inspection + annual inspection).
-
Strict scrapping standards : it is better to replace excessively than to use riskily.
-
Standardized operation : from disassembly to installation, the whole process complies with GB 6067.1 and the manufacturer's manual.
Remember: a qualified hook is the first line of defense for safe production!
The crane hook is the core load-bearing component of the lifting equipment. Its safety is directly related to the safety of personnel and equipment. To ensure that the hook is always in good condition, the maintenance and replacement standards must be strictly implemented. The following is a detailed maintenance inspection process, replacement standards and operating specifications.
1. Hook maintenance inspection process
1. Daily inspection (before each use)
-
Visual inspection :
-
Check the hook surface for cracks, deformation or severe rust.
-
Verify that anti-unhooking devices (such as spring locks) are intact and functioning properly.
-
-
Flexibility Check :
-
The hook should be able to rotate freely without sticking.
-
Check whether the bearings or pins are well lubricated.
-
-
Logo inspection :
-
Confirm that the rated load marking on the hook is clearly visible and not worn or altered.
-
2. Monthly inspection
-
Non-destructive testing (NDT) :
-
Magnetic particle testing (MT) : Detect surface cracks (especially hook neck and threaded areas).
-
Ultrasonic testing (UT) : Detect internal defects (such as slag inclusions, pores).
-
-
Size Measurements :
-
Use a caliper to measure the wear on the hook (if it exceeds 10% of the original size, it needs to be replaced).
-
Check for thread wear (for removable hooks).
-
3. Annual comprehensive inspection
-
Load test :
-
Conduct a static load test of 1.25 times the rated load (hanging for 10 minutes, no permanent deformation).
-
-
Rotating mechanism maintenance :
-
Disassemble and clean the bearing, and replace the grease (high temperature extreme pressure grease is recommended).
-
-
Third-party testing :
-
A test report shall be issued by a qualified organization (such as one that complies with GB/T 10051.1 standard).
-
2. Hook Replacement Standard
1. Compulsory scrapping conditions
If any of the following conditions occur, the hook must be replaced immediately:
-
Cracks : Visible cracks (even tiny) in any part.
-
Deformation :
-
The hook body is bent and deformed by more than 10°.
-
The hook width is worn more than 10% of the original size.
-
-
Thread damage : The threads used for connection are stripped, broken or severely worn.
-
Corrosion : The rust depth exceeds 5% of the original thickness (affecting the structural strength).
2. Recommended replacement cycle
| Usage Environment | Recommended replacement cycle | Remark |
|---|---|---|
| Normal working conditions (indoor) | 5~8 years | Regular check-ups without abnormalities can extend the |
| High frequency use (port) | 3-5 years | UT/MT testing every 2 years |
| Harsh environment (chemical) | 2~3 years | Additional monitoring of corrosion rates is required |
3. Hook replacement operation specifications
1. Preparation before replacement
-
Shutdown and power off : Make sure the power to the crane is turned off and hang a "No Operation" warning sign.
-
Load unloading : Remove all loads from the hook and place in a safe area.
-
Tool preparation :
-
Torque wrench (for threaded hook connections).
-
Hydraulic jack (heavy duty hook removal aid).
-
Wire rope cutter (if sling replacement is required).
-
2. Remove the old hook
-
To release the connection :
-
Use a torque wrench to remove the nut/pin (be sure to save the lock washer).
-
-
Check the mating surfaces :
-
Clean any rust or burrs on the mounting surface to ensure that the new hook fits tightly.
-
-
Recording issues :
-
Take photos of the damaged parts of the old hook and archive them for subsequent analysis.
-
3. Install new hook
-
Check specifications :
-
Confirm that the rated load and material of the new hook are consistent with those of the old hook (refer to GB/T 10051.1).
-
-
Lubrication and assembly :
-
Apply high-temperature grease (such as molybdenum disulfide) to threads and bearings.
-
Use a torque wrench to tighten according to the standard (e.g. M36 bolts require 1200 N·m torque).
-
-
Functional testing :
-
The rotational flexibility and anti-unhooking device are tested without load.
-
Carry out a 1.1 times dynamic load test (lifting/lowering 3 times).
-
4. Maintenance and replacement precautions
1. Safety Warning
-
Welding repair is prohibited : welding is not allowed after cracks appear on the hook, and it must be replaced.
-
Overloading is strictly prohibited : even if the appearance is intact, exceeding the rated load will be considered a violation.
-
Personnel training : Maintenance personnel must hold a special equipment operation certificate (such as Q3).
2. Spare parts management
-
Procurement channels : Choose suppliers with ISO 9001 certification and ask for material reports.
-
Inventory strategy :
-
Always have 1 to 2 hooks of the same model available (especially in high-frequency usage situations).
-
Old hooks must be destroyed after being scrapped (to prevent misuse).
-
3. Documentation
-
Maintenance log : record the date of each inspection, problems found and treatment measures.
-
Replacement report : includes the serial number of the new hook, test data and operator's signature.
V. Typical Case Analysis
Case 1: Hook thread slipping accident
-
Phenomenon : The hook in a workshop suddenly fell off when lifting 10t of cargo.
-
Cause : The threads were not lubricated for a long time, resulting in wear and tear, and were not replaced in time.
-
Lesson : Thread condition must be checked monthly and lock nuts must be used.
Case 2: Hook wear exceeds limit
-
Phenomenon : The width of the port hook was worn from 50mm to 58mm (the standard limit is 55mm).
-
Consequences : The sling came off and damaged the equipment.
-
Improvement : Install a hook wear scale to achieve visual monitoring.
VI. Conclusion
-
Prevention is better than emergency repair : discover hidden dangers in advance through regular inspections (daily inspection + monthly inspection + annual inspection).
-
Strict scrapping standards : it is better to replace excessively than to use riskily.
-
Standardized operation : from disassembly to installation, the whole process complies with GB 6067.1 and the manufacturer's manual.
Remember: a qualified hook is the first line of defense for safe production!
The crane hook is the core load-bearing component of the lifting equipment. Its safety is directly related to the safety of personnel and equipment. To ensure that the hook is always in good condition, the maintenance and replacement standards must be strictly implemented. The following is a detailed maintenance inspection process, replacement standards and operating specifications.
1. Hook maintenance inspection process
1. Daily inspection (before each use)
-
Visual inspection :
-
Check the hook surface for cracks, deformation or severe rust.
-
Verify that anti-unhooking devices (such as spring locks) are intact and functioning properly.
-
-
Flexibility Check :
-
The hook should be able to rotate freely without sticking.
-
Check whether the bearings or pins are well lubricated.
-
-
Logo inspection :
-
Confirm that the rated load marking on the hook is clearly visible and not worn or altered.
-
2. Monthly inspection
-
Non-destructive testing (NDT) :
-
Magnetic particle testing (MT) : Detect surface cracks (especially hook neck and threaded areas).
-
Ultrasonic testing (UT) : Detect internal defects (such as slag inclusions, pores).
-
-
Size Measurements :
-
Use a caliper to measure the wear on the hook (if it exceeds 10% of the original size, it needs to be replaced).
-
Check for thread wear (for removable hooks).
-
3. Annual comprehensive inspection
-
Load test :
-
Conduct a static load test of 1.25 times the rated load (hanging for 10 minutes, no permanent deformation).
-
-
Rotating mechanism maintenance :
-
Disassemble and clean the bearing, and replace the grease (high temperature extreme pressure grease is recommended).
-
-
Third-party testing :
-
A test report shall be issued by a qualified organization (such as one that complies with GB/T 10051.1 standard).
-
2. Hook Replacement Standard
1. Compulsory scrapping conditions
If any of the following conditions occur, the hook must be replaced immediately:
-
Cracks : Visible cracks (even tiny) in any part.
-
Deformation :
-
The hook body is bent and deformed by more than 10°.
-
The hook width is worn more than 10% of the original size.
-
-
Thread damage : The threads used for connection are stripped, broken or severely worn.
-
Corrosion : The rust depth exceeds 5% of the original thickness (affecting the structural strength).
2. Recommended replacement cycle
| Usage Environment | Recommended replacement cycle | Remark |
|---|---|---|
| Normal working conditions (indoor) | 5~8 years | Regular check-ups without abnormalities can extend the |
| High frequency use (port) | 3-5 years | UT/MT testing every 2 years |
| Harsh environment (chemical) | 2~3 years | Additional monitoring of corrosion rates is required |
3. Hook replacement operation specifications
1. Preparation before replacement
-
Shutdown and power off : Make sure the power to the crane is turned off and hang a "No Operation" warning sign.
-
Load unloading : Remove all loads from the hook and place in a safe area.
-
Tool preparation :
-
Torque wrench (for threaded hook connections).
-
Hydraulic jack (heavy duty hook removal aid).
-
Wire rope cutter (if sling replacement is required).
-
2. Remove the old hook
-
To release the connection :
-
Use a torque wrench to remove the nut/pin (be sure to save the lock washer).
-
-
Check the mating surfaces :
-
Clean any rust or burrs on the mounting surface to ensure that the new hook fits tightly.
-
-
Recording issues :
-
Take photos of the damaged parts of the old hook and archive them for subsequent analysis.
-
3. Install new hook
-
Check specifications :
-
Confirm that the rated load and material of the new hook are consistent with those of the old hook (refer to GB/T 10051.1).
-
-
Lubrication and assembly :
-
Apply high-temperature grease (such as molybdenum disulfide) to threads and bearings.
-
Use a torque wrench to tighten according to the standard (e.g. M36 bolts require 1200 N·m torque).
-
-
Functional testing :
-
The rotational flexibility and anti-unhooking device are tested without load.
-
Carry out a 1.1 times dynamic load test (lifting/lowering 3 times).
-
4. Maintenance and replacement precautions
1. Safety Warning
-
Welding repair is prohibited : welding is not allowed after cracks appear on the hook, and it must be replaced.
-
Overloading is strictly prohibited : even if the appearance is intact, exceeding the rated load will be considered a violation.
-
Personnel training : Maintenance personnel must hold a special equipment operation certificate (such as Q3).
2. Spare parts management
-
Procurement channels : Choose suppliers with ISO 9001 certification and ask for material reports.
-
Inventory strategy :
-
Always have 1 to 2 hooks of the same model available (especially in high-frequency usage situations).
-
Old hooks must be destroyed after being scrapped (to prevent misuse).
-
3. Documentation
-
Maintenance log : record the date of each inspection, problems found and treatment measures.
-
Replacement report : includes the serial number of the new hook, test data and operator's signature.
V. Typical Case Analysis
Case 1: Hook thread slipping accident
-
Phenomenon : The hook in a workshop suddenly fell off when lifting 10t of cargo.
-
Cause : The threads were not lubricated for a long time, resulting in wear and tear, and were not replaced in time.
-
Lesson : Thread condition must be checked monthly and lock nuts must be used.
Case 2: Hook wear exceeds limit
-
Phenomenon : The width of the port hook was worn from 50mm to 58mm (the standard limit is 55mm).
-
Consequences : The sling came off and damaged the equipment.
-
Improvement : Install a hook wear scale to achieve visual monitoring.
VI. Conclusion
-
Prevention is better than emergency repair : discover hidden dangers in advance through regular inspections (daily inspection + monthly inspection + annual inspection).
-
Strict scrapping standards : it is better to replace excessively than to use riskily.
-
Standardized operation : from disassembly to installation, the whole process complies with GB 6067.1 and the manufacturer's manual.
Remember: a qualified hook is the first line of defense for safe production!
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