Below-the-Hook Lifting Devices: Selection and Inspection

Engineering guide to below-the-hook lifting devices under ASME B30.20 and EN 13155: structural design categories, weld MPI non-destructive testing, and 125% proof load testing.

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Below-the-hook lifting devices—including spreader beams, lifting beams, C-hooks, sheet lifters, pallet forks, and vacuum lifters—are structural mechanical machines designed to connect crane hooks to specialized industrial loads. Governed by **ASME B30.20** and **EN 13155**, these devices are critical engineering assets whose structural design, fabrication, and maintenance require rigorous compliance with international safety codes. Unlike standard loose rigging hardware (such as shackles or eyebolts), below-the-hook devices are custom-engineered structures featuring welded joints, structural beams, and mechanical linkages. Rigging superintendents and safety managers must understand the structural design principles, statutory proof-load testing rules, and non-destructive examination (NDT) mandates governing below-the-hook hardware. ## Statutory Engineering and Manufacturing Standards Under ASME B30.20, below-the-hook lifters are categorized into two design categories based on service severity: - **Design Category A:** For severe, predictable loading environments where service conditions are mild and well-defined (Minimum Design Safety Factor = **3:1**). - **Design Category B:** For harsh, unpredictable industrial environments where dynamic shock loading and severe wear are anticipated (Minimum Design Safety Factor = **3:0 to 5:0**). ### Mandatory Markings and Nameplates: Every certified below-the-hook device must be fitted with a permanently welded or riveted metal namepla...