Summary
A C-hook is a lifting device that hangs below a crane hook and is used to lift items with a central opening, such as steel coils in a steel plant. Devices of this kind are covered by specific standards for design, marking, and inspection. This article explains the principles using standards and technical sources, then presents the manufacture of a C-hook for a 40-ton overhead crane by SFS (Steel Fabrication Solution), part of WCE’s CTE business unit, as a case study.

1. What is a C-hook?
A C-hook is a C-shaped lifting device whose lower carrying arm is inserted into the inner diameter of a coil, which is then lifted by crane. One manufacturer describes C-hooks as counterbalanced to hang level whether loaded or unloaded, often with pads to protect the coil surface [1].

2. Key principles
2.1 Standards for below-the-hook devices
ASME B30.20 covers structural and mechanical below-the-hook lifting devices, addressing marking, construction, installation, inspection, testing, maintenance, and operation [2]. Design is covered by ASME BTH-1, which includes lifting device classifications, structural design, and mechanical design [3].

2.2 Design categories and service classes
BTH-1 classifies devices by design category and service class [3]. A lifting equipment manufacturer explains that Design Category B applies to unpredictable or severe loading conditions, with a minimum 3:1 design factor, while the Service Class reflects the number of load cycles over the device’s life, which relates to fatigue [4]. Some mill-duty C-hooks are designed for Category B, Service Class 3 or 4 [1].

2.3 Marking and inspection
Below-the-hook devices must be marked with their rated load and inspected regularly, from visual checks before use to periodic inspections at least annually, or more often under severe service [4].

3. Case study: a 40-ton C-hook by SFS / CTE
– Scope: Manufacture of a C-hook for a 40-ton overhead crane through machining and steel fabrication
– Client: Leading steel sheet manufacturer in Thailand
– Duration: 2 May – 5 September 2026 (about 4 months)
– Progress: Plan 100% / Actual 100%, delivered to the client’s plant

The cover image shows the finished, painted C-hook hanging in a workshop. The left image shows the whole device with its lifting link and pins, while the right image shows the hook body in closer detail. All images were edited with AI so that no individuals or clients can be identified.

4. Observations
High-capacity lifting devices depend on accurate machining at load-bearing points, such as pin holes and pins, as well as sound fabrication quality. Local manufacturing allowed close coordination with the client and on-plan delivery.

5. WCE services
SFS (Steel Fabrication Solution), part of the CTE business unit, provides steel fabrication and machined components for industrial plants.
To discuss your project: +66 65-937-6283 | international@wce.co.th | www.wce.co.th
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References (accessed 6 Oct 2026)
[1] Bushman Equipment. C-Hooks (manufacturer brochure). https://www.bushman.com/wp-content/uploads/files/pdf/below-the-hook/brochures/bushman-c-hooks-brochure.pdf
[2] ANSI Blog (5 August 2025). ASME B30.20-2025: Below-the-Hook Lifting Devices. https://blog.ansi.org/ansi/asme-b30-20-2025-below-hook-lifting-devices/
[3] ASME (2023). ASME BTH-1–2023 Design of Below-the-Hook Lifting Devices (table of contents). https://www.asme.org/getmedia/92e0982b-1a65-4a8d-9009-7342b004e00f/BTH-1_2023_ToC.pdf
[4] Brozyna, H. (5 October 2020). Understanding Safety and Design Requirements of Below-the-Hook Lifters. CMCO (manufacturer article). https://cmco.com/en-us/resources/blog/understanding-safety-and-design-requirements-of-below-the-hook-lifters