Lubrication and rust prevention of crane hooks
The lubrication and rust prevention of crane hooks are key maintenance measures to ensure their long-term safe operation. The following is a systematic technical guide covering material selection, methods and precautions:
1. Lubrication management
1. Lubrication parts
-
Swivel bearing (if any): The bearing where the hook connects to the pulley block.
-
Threaded connection : the mating surface of the nut and the screw.
-
Anti-unhooking device : tongue hinge point and spring movable part.
2. Lubricant selection
-
High temperature and heavy load conditions :
-
Use molybdenum disulfide lithium grease (such as NLGI grade 2), which has a temperature resistance of up to 180°C.
-
Example: Shell Gadus S2 V220.
-
-
General environment :
-
General purpose lithium-based grease (such as NLGI grade 1) with strong adhesion.
-
-
Corrosive environment :
-
Greases containing anti-corrosion additives (such as Chevron SRI-2).
-
3. Lubrication cycle and method
| Location | Lubrication cycle | method |
|---|---|---|
| Rotary bearings | Every 500 hours | Use a high-pressure grease gun to inject until the old grease is squeezed out. |
| Threaded connection | Every 3 months | Apply a thin layer of grease to prevent seizure |
| Anti-unhooking device | per month | Spray lubricant (such as WD-40) |
4. Notes
-
Clean the surface before lubrication (remove old grease, dust).
-
Avoid grease contamination of the slings (wire rope/synthetic fiber slings).
2. Anti-rust treatment
1. Comparison of rust prevention methods
| method | Applicable scenarios | Pros and Cons |
|---|---|---|
| Galvanizing | High humidity, salt spray environment | Good durability (5-10 years), high cost |
| Anti-rust paint | Indoor or mildly corrosive environment | Easy to repair, requires regular inspection (repaint every 2 years) |
| Passivation treatment | Stainless steel hook | Improves oxidation resistance without changing appearance |
| Grease Covering | Short-term storage or spare hooks | Temporary protection, need to be reapplied regularly |
2. Operation steps
-
Surface treatment :
-
Remove rust by sandblasting or wire brushing (Sa2.5 cleanliness level).
-
Degrease with acetone or alcohol.
-
-
Coating construction :
-
Galvanizing: hot-dip galvanizing (thickness ≥ 80μm) or electroplating (20-30μm).
-
Paint: Epoxy primer + polyurethane topcoat (total dry film thickness ≥ 120μm).
-
3. Response to special circumstances
-
Marine environment : zinc-aluminum coating (such as Dacromet process) is used, and the salt spray resistance is > 1000 hours.
-
Chemical corrosion : sprayed fluorocarbon coating (PTFE), acid and alkali resistant.
3. Maintenance Taboos
-
Mixing lubricants : Different brands/types of grease may react chemically, causing failure.
-
Over-lubrication : The amount of grease injected into the bearing should not exceed 60% of the cavity volume (to prevent heating).
-
Ignoring thread rust prevention : Thread rust will make the hook unable to be disassembled, and thread anti-seizure agent (such as Loctite 8060) needs to be applied regularly.
4. Intelligent Monitoring Technology
-
Humidity sensor : monitors the humidity around the hook in real time and triggers an early warning.
-
Automatic lubrication system : Timed and quantitative grease injection, suitable for hooks at high altitude or in dangerous areas.
5. Standard reference
-
ISO 12944 : Standard for anti-corrosion coatings for steel structures.
-
GB/T 11376-2020 : Metal phosphate conversion film (anti-rust base treatment).
Summarize
-
Lubrication : Select appropriate lubricant and cycle according to the parts, and high-temperature grease is preferred for bearings.
-
Rust prevention : Choose galvanizing or coating according to the environment and check for peeling regularly.
-
Trend : Develop towards automated and intelligent maintenance to reduce the risk of manual intervention.
The lubrication and rust prevention of crane hooks are key maintenance measures to ensure their long-term safe operation. The following is a systematic technical guide covering material selection, methods and precautions:
1. Lubrication management
1. Lubrication parts
-
Swivel bearing (if any): The bearing where the hook connects to the pulley block.
-
Threaded connection : the mating surface of the nut and the screw.
-
Anti-unhooking device : tongue hinge point and spring movable part.
2. Lubricant selection
-
High temperature and heavy load conditions :
-
Use molybdenum disulfide lithium grease (such as NLGI grade 2), which has a temperature resistance of up to 180°C.
-
Example: Shell Gadus S2 V220.
-
-
General environment :
-
General purpose lithium-based grease (such as NLGI grade 1) with strong adhesion.
-
-
Corrosive environment :
-
Greases containing anti-corrosion additives (such as Chevron SRI-2).
-
3. Lubrication cycle and method
| Location | Lubrication cycle | method |
|---|---|---|
| Rotary bearings | Every 500 hours | Use a high-pressure grease gun to inject until the old grease is squeezed out. |
| Threaded connection | Every 3 months | Apply a thin layer of grease to prevent seizure |
| Anti-unhooking device | per month | Spray lubricant (such as WD-40) |
4. Notes
-
Clean the surface before lubrication (remove old grease, dust).
-
Avoid grease contamination of the slings (wire rope/synthetic fiber slings).
2. Anti-rust treatment
1. Comparison of rust prevention methods
| method | Applicable scenarios | Pros and Cons |
|---|---|---|
| Galvanizing | High humidity, salt spray environment | Good durability (5-10 years), high cost |
| Anti-rust paint | Indoor or mildly corrosive environment | Easy to repair, requires regular inspection (repaint every 2 years) |
| Passivation treatment | Stainless steel hook | Improves oxidation resistance without changing appearance |
| Grease Covering | Short-term storage or spare hooks | Temporary protection, need to be reapplied regularly |
2. Operation steps
-
Surface treatment :
-
Remove rust by sandblasting or wire brushing (Sa2.5 cleanliness level).
-
Degrease with acetone or alcohol.
-
-
Coating construction :
-
Galvanizing: hot-dip galvanizing (thickness ≥ 80μm) or electroplating (20-30μm).
-
Paint: Epoxy primer + polyurethane topcoat (total dry film thickness ≥ 120μm).
-
3. Response to special circumstances
-
Marine environment : zinc-aluminum coating (such as Dacromet process) is used, and the salt spray resistance is > 1000 hours.
-
Chemical corrosion : sprayed fluorocarbon coating (PTFE), acid and alkali resistant.
3. Maintenance Taboos
-
Mixing lubricants : Different brands/types of grease may react chemically, causing failure.
-
Over-lubrication : The amount of grease injected into the bearing should not exceed 60% of the cavity volume (to prevent heating).
-
Ignoring thread rust prevention : Thread rust will make the hook unable to be disassembled, and thread anti-seizure agent (such as Loctite 8060) needs to be applied regularly.
4. Intelligent Monitoring Technology
-
Humidity sensor : monitors the humidity around the hook in real time and triggers an early warning.
-
Automatic lubrication system : Timed and quantitative grease injection, suitable for hooks at high altitude or in dangerous areas.
5. Standard reference
-
ISO 12944 : Standard for anti-corrosion coatings for steel structures.
-
GB/T 11376-2020 : Metal phosphate conversion film (anti-rust base treatment).
Summarize
-
Lubrication : Select appropriate lubricant and cycle according to the parts, and high-temperature grease is preferred for bearings.
-
Rust prevention : Choose galvanizing or coating according to the environment and check for peeling regularly.
-
Trend : Develop towards automated and intelligent maintenance to reduce the risk of manual intervention.
The lubrication and rust prevention of crane hooks are key maintenance measures to ensure their long-term safe operation. The following is a systematic technical guide covering material selection, methods and precautions:
1. Lubrication management
1. Lubrication parts
-
Swivel bearing (if any): The bearing where the hook connects to the pulley block.
-
Threaded connection : the mating surface of the nut and the screw.
-
Anti-unhooking device : tongue hinge point and spring movable part.
2. Lubricant selection
-
High temperature and heavy load conditions :
-
Use molybdenum disulfide lithium grease (such as NLGI grade 2), which has a temperature resistance of up to 180°C.
-
Example: Shell Gadus S2 V220.
-
-
General environment :
-
General purpose lithium-based grease (such as NLGI grade 1) with strong adhesion.
-
-
Corrosive environment :
-
Greases containing anti-corrosion additives (such as Chevron SRI-2).
-
3. Lubrication cycle and method
| Location | Lubrication cycle | method |
|---|---|---|
| Rotary bearings | Every 500 hours | Use a high-pressure grease gun to inject until the old grease is squeezed out. |
| Threaded connection | Every 3 months | Apply a thin layer of grease to prevent seizure |
| Anti-unhooking device | per month | Spray lubricant (such as WD-40) |
4. Notes
-
Clean the surface before lubrication (remove old grease, dust).
-
Avoid grease contamination of the slings (wire rope/synthetic fiber slings).
2. Anti-rust treatment
1. Comparison of rust prevention methods
| method | Applicable scenarios | Pros and Cons |
|---|---|---|
| Galvanizing | High humidity, salt spray environment | Good durability (5-10 years), high cost |
| Anti-rust paint | Indoor or mildly corrosive environment | Easy to repair, requires regular inspection (repaint every 2 years) |
| Passivation treatment | Stainless steel hook | Improves oxidation resistance without changing appearance |
| Grease Covering | Short-term storage or spare hooks | Temporary protection, need to be reapplied regularly |
2. Operation steps
-
Surface treatment :
-
Remove rust by sandblasting or wire brushing (Sa2.5 cleanliness level).
-
Degrease with acetone or alcohol.
-
-
Coating construction :
-
Galvanizing: hot-dip galvanizing (thickness ≥ 80μm) or electroplating (20-30μm).
-
Paint: Epoxy primer + polyurethane topcoat (total dry film thickness ≥ 120μm).
-
3. Response to special circumstances
-
Marine environment : zinc-aluminum coating (such as Dacromet process) is used, and the salt spray resistance is > 1000 hours.
-
Chemical corrosion : sprayed fluorocarbon coating (PTFE), acid and alkali resistant.
3. Maintenance Taboos
-
Mixing lubricants : Different brands/types of grease may react chemically, causing failure.
-
Over-lubrication : The amount of grease injected into the bearing should not exceed 60% of the cavity volume (to prevent heating).
-
Ignoring thread rust prevention : Thread rust will make the hook unable to be disassembled, and thread anti-seizure agent (such as Loctite 8060) needs to be applied regularly.
4. Intelligent Monitoring Technology
-
Humidity sensor : monitors the humidity around the hook in real time and triggers an early warning.
-
Automatic lubrication system : Timed and quantitative grease injection, suitable for hooks at high altitude or in dangerous areas.
5. Standard reference
-
ISO 12944 : Standard for anti-corrosion coatings for steel structures.
-
GB/T 11376-2020 : Metal phosphate conversion film (anti-rust base treatment).
Summarize
-
Lubrication : Select appropriate lubricant and cycle according to the parts, and high-temperature grease is preferred for bearings.
-
Rust prevention : Choose galvanizing or coating according to the environment and check for peeling regularly.
-
Trend : Develop towards automated and intelligent maintenance to reduce the risk of manual intervention.
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