This combines the two features that matter most on an unsupervised lift. The self locking latch stays shut under load and releases only through a deliberate action with the load removed, so the hook cannot come undone while out of sight. The ball bearing swivel turns with weight on it, letting accumulated twist out of the sling rather than winding it up. Grade 8 alloy steel to BS EN 1677-3, the standard specific to self locking hooks, in eight sizes from 6 mm to 26 mm chain.
Key Features
- Positive self locking action: The latch locks under load and cannot be pushed open the way a sprung safety catch can. Release requires a deliberate two-handed operation with the load off.
- Rotation under load: Stated explicitly by the manufacturer. A plain swivel locks solid the moment weight comes on; a bearing swivel keeps turning and releases twist as it develops.
- BS EN 1677-3: The part of the standard covering self locking hooks specifically, assessing the locking mechanism rather than just hook strength.
- Eight sizes: Chain 6, 8, 10, 13, 16, 20, 22 and 26 mm.
- Grade 8 alloy steel: Quenched and tempered, in the Cobra red finish.
- Full traceability marking: Material grade, manufacturer's identification, size, product ID mark and traceability code.
Technical Specifications
| Product Code |
Chain Dia (mm) |
| CG8SSLH6U |
6 |
| CG8SSLH8U |
8 |
| CG8SSLH10U |
10 |
| CG8SSLH13U |
13 |
| CG8SSLH16U |
16 |
| CG8SSLH20U |
20 |
| CG8SSLH22U |
22 |
| CG8SSLH26U |
26 |
Full dimensional data and Working Load Limits by chain size are given on the user information sheet. The U suffix denotes the ball bearing version.
BS EN 1677-3 | Grade 8 | Self Locking | Rotation Under Load | LOLER Ready
Grade 8 alloy steel conforming to BS EN 1677-3, the standard specific to self locking hooks. Ball bearing swivel suitable for rotation under load. Rated -20 °C to +200 °C. Each hook is marked with material grade, manufacturer's identification, size, product ID mark and traceability code, and supplied with a certificate. Under LOLER 1998, lifting accessories require thorough examination by a competent person at intervals not exceeding 12 months.
Suitable Applications
The combination of self locking and bearing swivel suits lifts that are both unsupervised and prone to rotation, which describes a good deal of construction and industrial work: blind lifts where the hook is out of sight, loads that turn as they leave the ground, long or asymmetric items, work over occupied areas, offshore and marine lifting, and long-duration suspended loads. It is the specification to reach for when the answer to "what if it turns and nobody is watching" needs to be nothing. Where the hook is watched throughout and the load hangs still, a plain sling hook does the job for a great deal less.
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 the Swivel Self Locking Hook
- Match to the chain size: Connect through a coupling link or component connector sized to the chain.
- Check both mechanisms before every lift: The latch must lock positively and release only through the deliberate two-handed action; the swivel must rotate smoothly by hand.
- Seat the load in the throat: Load bears in the throat, never on the tip. Confirm the latch has locked before taking the weight.
- Release only with the load off: The mechanism is designed not to release under load and forcing it will damage it.
- Let the swivel relieve twist: It is not a means of deliberately rotating a suspended load.
- Never repaint: Paint entering the latch mechanism is the most common cause of a self locking hook failing to lock.
Warning: Never use a self locking hook whose mechanism does not lock positively. Never attempt to release the latch under load. Never repaint, as paint in the mechanism prevents locking while the hook still looks closed. Never tip load.
Safety Information
- Confirm the locking mechanism engages positively before every lift.
- Confirm the swivel bearing rotates freely before every lift.
- Use only with Grade 8 chain and components of the matching size.
- Load must bear in the throat, never on the tip.
- Do not release the latch while under load.
- Withdraw if the latch fails to lock, the swivel is stiff or seized, or the hook shows throat opening or distortion.
- Never weld, heat treat, machine or repaint.
- Operating range -20 °C to +200 °C.
- Thorough examination by a competent person required at intervals not exceeding 12 months under LOLER 1998.
Inspection and Maintenance
Two mechanisms, and both fail for the same two reasons: grit and paint. The latch must lock positively every time and require the full two-stage action to release; a mechanism that opens with one movement has failed regardless of appearance. The swivel bearing must rotate smoothly with no notchiness, grinding or axial play, since a bearing that has begun to fail will seize under load and defeat the point of buying it. Never repaint the hook. Beyond the mechanisms, measure throat opening against the original dimension, check the tip and throat for gouging, and confirm the marking is legible.
Downloads
Frequently Asked Questions
Q: What does the U in the code mean?
It denotes the ball bearing version. CG8SSLH is the standard swivel self locking hook; the U codes have the bearing swivel that rotates under load. If twist is your problem, you want the U.
Q: Self locking or a safety catch?
A safety catch stops the load falling off when the sling goes slack, but it can be pushed open. A self locking latch cannot: it locks under load and releases only deliberately with the load removed. Choose self locking where the hook is out of sight during the lift or where accidental release would be serious.
Q: Why does repainting matter so much?
Paint in the latch pivot can stop it locking fully while still appearing closed, which is the worst possible failure because it is invisible. It also conceals cracks and wear. If the red finish has worn, that is cosmetic. Never repaint a lifting component.
Q: Why -20 °C when the rest of Cobra Grade 8 is -40 °C?
The swivel bearing is likely the limiting component rather than the alloy steel, which is why the plain fittings in the range carry the colder rating. If you are working below -20 °C, check the marking on the individual component rather than relying on the range-wide figure.
