Over the last few years, the global material handling equipment manufacturing sector has witnessed a steady growth owing to the increasing demand. Fortunately, the trend is likely to continue in the coming years.
According to a recent study, global demand for material handling equipment is forecast to grow 3.9% per year through 2023 to reach $190 billion, faster than the pace of growth from 2013 to 2018. The growth is attributed to multiple trends, including increasing automation of the manufacturing, mining, and construction sectors.
One of the critical elements of most material handling systems is below-the-hook (BTH) devices. With these devices, you can easily enhance the efficiency of your cranes, enabling them to handle a wide range of loads.
Let’s see what below-the-hook devices are and why they matter.
A typical below-the-hook device is a mechanical device or tool that you can attach to cranes, hoists, or any other lifting equipment. It helps you to secure the loads safely when moving them.
A below-the-hook device can be anything, including magnets, hooks, ladle hooks, coil grabs, spreader beams, clamps, sheet and plate lifter, drum tilters, and lifting tongs, among others. The type, structure, and load capacity of these devices varies depending on the application. You can also find customized devices designed for very specific purposes.
Although you can get customized solutions, these devices are also used for a few common applications. These include:
Although each below-the-hook device is different depending on the application, there are a few components that you can find everywhere.
Lifting lugs are projections in the plate or bar or any heavy component of a below-the-hook device. The number and location of lifting lugs vary. They usually have an opening or hole in the center. You can attach hooks, slings, and ropes through these openings to tie the load to the device.
Bail is the point where the below-the-hook device connects with the crane hook or the hoist. Bails usually come in two styles, pin style and plate style. The number and location of bails will vary from device to device.
It is a simple component that holds the lifter in an open or closed position. The primary purpose of the latch is to prevent the load from getting off suddenly to keep the equipment and workers safe. The most common example is using safety latches on the hooks.
A typical gusset is usually a metal plate attached to the device to provide it with added strength. It protects the area facing excessive stress or rough usage from breaking down under the weight.
Each below-the-hook device is application-oriented. As a result, it comes with a specific set of advantages. However, the following are the most common ones:
A. Safety
Perhaps the biggest benefit of a below-the-hook device is safety. Although you can use wire rope slings, synthetic slings, and alloy metal chain slings to lift and move any load, they may not necessarily be the safest option out there.
These lifting devices may cause the load to shift suddenly while it is still in the air, resulting in a potentially disastrous accident. They may also cause irrecoverable damage to the goods. Both equipment and workers are at risk in these circumstances.
However, as a below-the-hook device is specifically designed to move and lift a load, it takes care of all safety concerns. Furthermore, you don’t have to spend time or money on coming up with an alternative that may or may not work.
B. Efficiency
The second advantage is that you can get customized below-the-hook devices. Most manufacturers do offer specialized solutions as per your material handling system requirements. So, it is easier to move your load safely and efficiently without wasting time, energy, and money. Plus, as the load is not damaged during the lift, its integrity remains intact.
However, as these devices are made for heavy lifting and moving applications, you need to follow the required safety guidelines.
When it comes to below-the-hook devices, the American Society of Mechanical Engineers (ASME) has set a few strict quality standards. The following are the two most critical standards that your device must comply with:
A. ASME B30.20
This ASME standard covers the provisions for marking, construction, installation, inspection, testing, maintenance, and operation of below-the-hook lifting devices. It covers the guidelines and standards not covered in any of the other B30 volumes.
It addresses the following five below-the-hook devices.
B. ASME BTH-1
In this section, ASME provides the minimum structural and mechanical design and electrical component selection criteria required for the B30.20 below-the-hook lifting devices. It addresses only the design requirements. So, you need to use the standards mentioned in BTH-1 in combination with those provided in B30.20.
Furthermore, you need to use the BTH-1 and B30.20 in combination with other volumes of the ASME B30 series to comply with the regulations in your respective jurisdiction.
Below-the-hook devices are one of the most critical elements in material handling systems. They provide your workers and equipment with the required safety and efficiency. Hopefully, this post will offer you the much-needed insights about below-the-hook devices. Let us know if you have found this article useful in the comments section.
Shop Online HardwareA below-the-hook (BTH) device is any mechanical attachment - hook, clamp, magnet, spreader beam, coil grab, or specialty lifter - that connects a crane or hoist to the load being moved. The term distinguishes these devices from the overhead equipment (the crane or hoist itself). Below-the-hook devices are governed by ASME B30.20 (Below-the-Hook Lifting Devices) and ASME BTH-1 (Design of Below-the-Hook Lifting Devices), which address marking, inspection, and minimum design criteria. Browse Lifting Hardware At Holloway Houston
A shank hook has a fixed shank that mounts directly to a hoist or trolley - the hook body is attached to the rigging assembly and does not rotate independently of the attachment point. A swivel hook is mounted on a swivel mechanism that allows the hook to rotate freely in relation to the attachment point, which prevents load spin from transmitting into the hoist chain or cable above it. The appropriate type depends on the application, the nature of the lift, and whether load rotation is expected. Manufacturer documentation covers the rated configuration and limitations for each type under ASME B30.10.
The safety latch is a spring-loaded keeper device that spans the throat of the hook to prevent rigging - sling eyes, wire rope, shackles - from accidentally exiting the hook under slack or sudden load shifts. The latch does not contribute to the hook's rated lifting capacity. Published industry guidance and ASME B30.10 address hook latch requirements for overhead lifting applications. Some hook designs also incorporate positive locking latches for applications where the load direction is variable or where the connection must remain secure against inadvertent opening.
Inspection programs for rigging hooks under ASME B30.10 typically identify removal criteria around deformation of the hook body, cracks, excessive wear at the bearing surface, throat opening that has widened beyond the manufacturer's specified limit, damaged or inoperable safety latches, and illegible identification markings. Hook throat opening is a particularly common measurement point - overloading can stretch the hook and widen the throat without other visible deformation. Product-specific discard criteria follow the applicable manufacturer documentation. Holloway Houston's inspection services handle documented periodic inspections for rigging hardware.
Industrial lifting hooks are typically forged from alloy or carbon steel. Forged hooks are generally preferred for overhead lifting applications because the forging process aligns the grain structure of the steel along the load path, producing a more uniform strength characteristic than a casting. Cast hooks may be appropriate for certain applications at lower load ranges, but the manufacturer's documentation and applicable ASME B30.10 criteria govern the rated use conditions for each product. Hooks should be identified by their markings - if a hook's material or manufacturing process is unknown, it should not be used in overhead lifting until its provenance and rating can be confirmed.
The content provided is for general informational purposes only and is not a substitute for professional advice. Holloway Houston, Inc. is not responsible for any actions taken based on this information.