Introduction
The double-girder fully-enclosed hook block consists of hook, pulley set, pulley shaft, crossbeam, bearings, fully-enclosed housing and anti-fall device. The hook is forged from high-quality carbon steel or alloy steel, with high strength and good toughness after heat treatment; pulleys are made of cast iron or cast steel, with machined rope grooves, wear-resistant and durable; crossbeam adopts high-strength alloy steel, with strong load capacity. The fully-enclosed housing completely encloses moving parts such as pulleys and bearings, effectively preventing dust, foreign objects and rainwater intrusion, extending the service life of bearings and pulleys, while avoiding safety hazards such as wire rope and pulley hand pinching, with clean and aesthetic appearance. During operation, the wire rope passes through the pulley set, transmitting the lifting force to the hook through the reeving mechanism to achieve heavy object lifting; the double-girder hook block is connected to the trolley frame through the crossbeam, suitable for large-tonnage lifting equipment such as double-girder bridge cranes, double-girder gantry cranes and metallurgical cranes. The hook is equipped with an anti-fall pawl to prevent accidental unhooking of slings; pulleys are equipped with anti-rope-off baffles to prevent wire rope . The double-girder fully-enclosed hook block is widely used in double-girder lifting equipment in industries such as machining, metallurgy, mining, ports and power, serving as the core lifting device for large-tonnage heavy object lifting.
Application


Our Advantage
Adopts a fully-enclosed housing to completely enclose moving parts such as pulleys and bearings, effectively preventing dust, foreign objects and rainwater intrusion, extending the service life of bearings and pulleys; while avoiding safety hazards such as wire rope and pulley hand pinching, with clean and aesthetic appearance, especially suitable for dusty and harsh environment occasions such as metallurgy, mining and cement plants.
Specially designed for double-girder bridge/gantry cranes, the crossbeam is rigidly connected to the trolley frame with uniform force and strong load capacity; pulley set reeving ratio 2~10, can amplify lifting force by 2~10 times, adapting to 5t~200t large-tonnage heavy object lifting, far superior to single-girder hook blocks, serving as an ideal lifting device for double-girder large-tonnage lifting equipment.
Adopts multi-pulley set structure, uniformly distributing the lifting force to multiple wire ropes through the reeving mechanism, with small force on a single wire rope and long wire rope service life; pulleys are made of cast iron or cast steel, with precision-machined rope grooves, good fit with wire rope, stable operation, low noise and small wear, greatly improving the operating stability and service life of the hook block.
The hook is integrally forged from high-quality carbon steel or alloy steel, normalized and tempered, with high tensile strength, good toughness and impact resistance; each hook undergoes magnetic particle inspection and load test, safety factor ≥4 times, tested via 1.25× rated load static test, ensuring safe heavy-load lifting; equipped with an anti-fall pawl to prevent accidental unhooking of slings, safety performance far superior to welded hooks.
The fully-enclosed housing is equipped with a detachable inspection cover, allowing inspection of pulley, bearing and wire rope status without overall disassembly, convenient for maintenance; bearings adopt self-lubricating or regular oil lubrication, with long lubrication cycle; key components such as pulleys, hooks and crossbeams are all made of high-strength materials, normal service life over 10 years, low comprehensive maintenance cost and long whole machine service life.
Specification
| Parameter | 5~10t | 16~32t | 50~100t | 160~200t |
| Rated Capacity | 5/10t | 16/20/32t | 50/80/100t | 160/200t |
| Number of Pulleys | 2 pcs | 4 pcs | 6~8 pcs | 8~10 pcs |
| Reeving Ratio | 2 | 4 | 6~8 | 8~10 |
| Wire Rope Dia. | Φ11~Φ14mm | Φ14~Φ18mm | Φ18~Φ24mm | Φ24~Φ32mm |
| Pulley Dia. | Φ250~Φ350mm | Φ350~Φ500mm | Φ500~Φ710mm | Φ710~Φ1000mm |
| Hook Type | Single hook | Single hook / Double hook | Double hook | Double hook |
| Safety Factor | ≥4 | ≥4 | ≥4 | ≥4 |
| Hook Material | 20# steel / 20CrMnTi | Same as left | Same as left | Same as left |
| Pulley Material | Cast iron / Cast steel | Cast steel | Cast steel | Cast steel |
| Crossbeam Material | 45# steel / 40Cr | Same as left | Same as left | Same as left |
| Antifall Device | Anti-drop pawl + anti-drop rope baffle | Same as left | Same as left | Same as left |
| Weight | 0.2~0.5t | 0.5~1.5t | 1.5~4t | 4~8t |
| Applicable Crane | 5-20t double-girder crane | 20-50t double-girder crane | 50-100t double-girder crane | Over 100t double-girder / metallurgical crane |


