A shortening clutch takes up a chain leg and holds it captive — the chain seats fully into the body and is pinned, rather than resting in an open throat as it would in a grab hook.
That distinction matters where the leg may go slack or the sling stays rigged between lifts. A grab hook holds by load and geometry; if the leg goes slack, the link can lift out. A clutch cannot release until it is deliberately opened.
Temperature: this fitting is rated -40 °C to +400 °C. That is the wide Kito rating, suitable for foundry, forge and heat treatment work, with reductions in Working Load Limit above +200 °C.
Key Features
- Captive chain seating: The chain seats fully into the body and is pinned, rather than resting in an open throat
- Cartec range: Red painted finish identifies the range on site
- BS EN 1677-1: The applicable standard for this fitting type
- -40 °C to +400 °C: With derating above +200 °C
- 4 sizes: Full data in the information sheet
- Fully marked and certificated: Grade, manufacturer’s ID, size and traceability code
Technical Specifications
| Product Code |
Chain Dia (mm) |
Part No. |
A/B (mm) |
C (mm) |
D (mm) |
E (mm) |
F (mm) |
P (mm) |
| G8CSC8 |
8 |
CX08 |
9.5 |
10 |
9.5 |
23.5 |
56 |
10 |
| G8CSC10 |
10 |
CX10 |
12.5 |
14 |
12 |
25 |
88 |
13 |
| G8CSC13 |
13 |
CX13 |
16.5 |
17 |
15 |
32.5 |
115 |
16 |
| G8CSC16 |
16 |
CX16 |
20.5 |
19 |
19 |
39 |
143 |
21 |
Working Load Limits and full dimensional data are in the information sheet.
BS EN 1677-1 | Grade 8 | -40 °C to +400 °C | LOLER Ready
Conforms to BS EN 1677-1. Grade 8 alloy steel with a red painted finish. Marked with material grade, manufacturer’s identification, size, product ID mark and traceability code, and supplied with a certificate. Rated -40 °C to +400 °C, with reductions in Working Load Limit above +200 °C. Under LOLER 1998, thorough examination by a competent person at intervals not exceeding 12 months.
Suitable Applications
Used where a chain leg needs shortening securely and the sling may stay rigged between lifts, or where the leg could go slack in service. Where quick field adjustment matters more than captive seating, a grab hook is faster.
More About This Product
Shackles are the most-handled component in any lifting operation, and that is precisely why they wear out first. A sling gets rigged and derigged; a shackle gets rigged, derigged, dropped, driven over, thrown into a box and picked up by whoever needs one. Most lifting gear fails from a single overload; shackles fail from accumulated inattention.
The grade markings matter more than most people realise. A Grade 6 high tensile shackle to BS EN 13889 and a Grade 8 alloy shackle look similar and share the same body shape, but the alloy version carries considerably more at the same size. Once a shackle is in a box with fifty others, the only way to tell them apart is the marking — which is why an unmarked shackle has to be scrapped no matter how good it looks.
Understanding the Load Path
A shackle has two distinct load-bearing elements and they do different jobs. The bow takes the sling; the pin takes the load. Reverse that — put the sling on the pin and the load on the bow — and two things happen. The sling bears on a smaller radius than it was designed for, and any movement in the sling starts to rotate the pin.
On a screw collar pin that rotation is the failure mechanism. A sling shifting under a settling load, or vibration transmitted from plant nearby, will slowly unscrew the pin over minutes or hours. It rarely happens quickly enough for anyone to see it happening.
The second consideration is angle. A shackle loaded in line with the pin carries its full rating. Loaded at an angle across the bow it carries substantially less, and published derating tables cover a limited range of angles — beyond that range no figure is published because none applies. On a multi-leg sling every leg is at an angle by definition, which is why the bow shackle exists and why putting a multi-leg sling into a dee shackle is a genuine mistake rather than a preference.
How to Use
- Match the chain size and grade: One diameter, one grade throughout the assembly.
- Seat the chain fully and pin it: The chain must seat home in the body before the pin is fitted.
- Seat the load in the throat: Load bears in the throat, never on the tip.
- Check the temperature rating: -40 °C to +400 °C on this fitting.
- Recertify after building or altering an assembly: Proof testing and certification by a competent person is required.
- Do not modify: Never weld, heat, machine, drill or repaint.
Warning: Never tip load. Never use a hook with a missing or damaged safety catch.
Safety Information
- Never exceed the marked Working Load Limit.
- Use components of the same grade throughout the assembly.
- Load must bear in the throat, never on the tip.
- Operating range -40 °C to +400 °C, with derating above +200 °C.
- Withdraw any fitting showing wear beyond the manufacturer’s stated limit, distortion, cracks or elongation.
- Never weld, heat treat, machine or repaint.
- Assemblies built or altered require proof testing and recertification.
- Thorough examination by a competent person required at intervals not exceeding 12 months under LOLER 1998.
Inspection and Maintenance
Confirm the chain seats fully into the body and the pin engages cleanly. Measure the body at its bearing points against original dimensions and withdraw at the manufacturer’s stated wear limit. Check the pins for straightness and full engagement and the pin bores for elongation, which is the first sign of overload. Look for distortion and cracking at the point of maximum curvature, and confirm the grade marking and traceability code remain legible.
Downloads
Frequently Asked Questions
Q: What is the difference between a clutch and a grab hook?
A grab hook holds a link in an open throat by load and geometry; if the leg goes slack the link can lift out. A clutch seats the chain fully into the body and pins it captive. Use a clutch where the leg may go slack or the sling stays rigged.
Q: How does the temperature rating compare?
This fitting is -40 °C to +400 °C. The Kito ranges run to +400 °C; Cobra and Green Pin stop at +200 °C. For foundry or heat treatment work that difference decides which range you can use.
Q: Can I mix this with other grades?
Physically yes, but the assembly must then be derated to the lower grade, marked accordingly and recertified. Simpler to keep an assembly to one grade.
Q: Why must I not repaint it?
The red finish identifies the range, and paint conceals the cracks and wear an inspection is looking for. Repainting a lifting fitting is grounds for withdrawal.
