Contributed by Bob Kozickie, Technical Sales Support Manager
Edited by Christy Kutchma, Product & Marketing Associate

Plate steel is an essential component that is used to fabricate everything from railroad tanker cars, pressure vessels, and storage tanks to machinery, medical equipment, and fighter jets. It is produced in a myriad of widths, lengths, and thicknesses. The metallurgical grades also vary in availability within these parameters from carbon to stainless to titanium just to name a few.

Since the plate sizes can vary so greatly, there are two lifting components used to transfer steel plate safely – Plate Hooks and/or Sheet Lifters.

Plate Hooks

Like other hooks used for lifting, plate hooks must also be compliant with all of the governing standards such as ASME and OSHA. ASME B30.10-2019 Hooks, is recognized by OSHA as the leading standard for compliance. ASME has established the criteria for plate hook design, identification, and proof testing.

Standard Plate hooks are designed to have a 45 degree angle to the load. The bottom (shoe) is designed with a 5-10 degree upward angle and the hooks’ back offsets this angle when lifting the load. Special custom plate hooks can be designed for situations that have headroom concerns which require a constant 45 or 30 degree angle of lift. Those hooks are commonly much thicker than standard plate hooks due to additional stresses that the hook will encounter. As the angle of lift is decreased, the plate hooks will appear to look similar in shape to Pipe Lifting Hooks. Even with these decreased angle circumstances, the lifting angle of the plate hook must be maintained between the load and the chain sling leg to assure a safe lift.

There are common safety concerns when using plate hooks. The possibility exists that the rigger can get their hand pinched or smashed while engaging a plate hook onto the load. A safe and ergonomic option that is often used to address these issues is to install a handle onto the back of the hooks. The handle is welded into the body of the back plate prior to heat treat and testing in compliance with ASME B30.10 requirements. Installing handles significantly decreases the number of reported bodily injury incidents in the workplace.

Chain sling assemblies with plate hooks are almost always manufactured in 2, 3, and 4 leg configurations. When lifting square or rectangular plate, these assemblies are always used in pairs on opposite sides to maintain level lifting. Plates are however often cut into rounds, triangles, or other shapes that may require an odd number of legs to safely secure the load while lifting. There can also be applications when using a lifting beam where multiple single-leg slings are attached to various connection points across the length of the beam. This application is commonly used for significantly long sheets or plates.

plate hook diagramWhen using standard catalog plate hooks, the chain sling assembly must be rated at 60 degrees between the load and chain leg. The chain slings that are used in conjunction with plate hooks should also always be made with adjusters to shorten the chains length. This is the general industry practice that is followed by rigging shops manufacturing alloy chain slings with plate hook attachments. Adjusters are added to assure that the lifting angle that the hook is designed to lift is maintained regardless of the width of the plate being lifted. Commonly, the end user is lifting sheets of steel with varying widths for different applications. The chain sling needs to be adjusted by the rigger to accommodate the 60 degree angle. The main objective of the rigger is to assure that there is a straight line pull from the master link to the top of the plate hook and maintain a bearing to bearing contact between the plate hook shoe and the bottom facing of the steel plate. If the angle is too great or too small, the hook has a much greater chance of a catastrophic failure or “kicking out” and dropping the load. This is the most common reason for plate hook deformation and failures.

All plate hooks are also manufactured using Grade 80 Steel and heat treat processes. There is no provision written within the Standards for manufacturing Plate Hooks or J-Hooks as Grade 100 components. An example of this is a Peerless PHA 050 Standard Plate Hooks to be used with 1/2” alloy chain. These are rated at 13,000 Lbs. which is slightly higher than the 12,000 lb. capacity for 1/2” Grade 80 Alloy Chain but significantly less than the 15,000 lb. Grade 100 rating. Custom Plate Hooks can be engineered and proof tested to Grade 100 capacities. The chain sling can then be assembled and rated to the Grade 100 WLL Peerless engineers can design these chain sling assemblies if the applications requirement warrants the higher capacity.