Wire rope anchorages and fittings

Shackles and eyebolts

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Use this page as a guide to working safely with shackles, eyebolts and eyenuts.

What are shackles?

Shackles are a portable link used for joining various pieces of lifting equipment. The two main shapes for load lifting are the "dee" and "bow" shackles.

Most shackles are made of round bar and have circular eyes. The pin of the common shackle screws directly into one eye and should have a collar.

In some shackles, the pins pass clear through both eyes and are secured by a split pin forelock (split flat cotter pin) or nut and split pin.

The nominal size of a tested shackle refers to the body diameter. All tested shackles have a pin larger than the body.

Shackles are made to AS2741 Shackles. The most common grades are 'S' and 'T' for dee and bow shackles. To remove any projections, shackle pins are sometimes counter sunk flush with the eyes.

The pin-and-forelock shackle is a safety shackle. However, it is mainly used for standing rigging. This could include:

guys
applications where you can't see the connection
when it may be subject to vibration that might cause a screw pin to undo.

Example of dee shackle

Example of bow shackle

Using shackles safely

Here's what to consider to safely use shackles:

Working load limit

Shackles must be branded with the working load limit (WLL). Do not use a shackle for load lifting without the WLL clearly marked.

Capacity

Always use the correct size shackle or correct working load limit to match the rigging equipment or work you are undertaking.

Wear

Do not use a shackle if it is worn in the crown or on the pin by more than 10% of its original diameter.

Deformation

Do not use a shackle or pin which is bent, strained, deformed or damaged. Small microscopic cracks may have developed during deformation. These can extend under quite small loads and lead to complete failure.

Tightening

Screw shackle pins should be hand tightened, then loosened by a quarter turn. This is so that the shackle pin can be unscrewed when the weight is released. If the pins are tightened and the strain is taken on the shackle, the pin often jam and is difficult to unscrew.

Vibration

Shackles might be subject to vibration. For example, when used on:

conveyors
counter weight take up towers
permanent lifting gear
lifting beams
luffing bridle pendants.

If a shackle needs to be left in position and has the potential to vibrate loose, you can secure it by mousing the pin to the body.

A better option for this situation is to use a safety pin style shackle.

Never swap the pin of a shackle with an alternative pin or nut.

Inspection

When inspecting shackles, here's what you should check:

markings (WLL, manufacturer, size in mm, batch test number, grade of steel)
wear
straightness
that the pin is always seated
that the shackle is not deformed or opening up

Vertical force

Shackles are designed to take vertical forces only. Diagonal forces will strain the shackle and lead to eventual failure.

Tilting

If any small object (such as a single sling or another shackle) is placed on the pin the shackle will tilt, slant or cant.

To stop this happening, pack the shackle pin with washers or ferrules to keep the load in the centre of the pin.

Multiple slings

When using multiple slings, always use a bow shackle large enough for all the eyes safely on the bow. The pin of the shackle should rest on the hook.

A bow shackle can accommodate a maximum of 2 slings at a maximum of 60 degrees.

The pin of the shackle will be applied on the hook, so as it is axially loaded. Refer to AS2741.

Eye bolts and eye nuts

Grade 40 forged collared eyebolts and eyenuts for lifting are covered by AS2317.

The eyenuts can be used for lifting so long as the material and thread that the eyenut is fitted to has the same or greater capacity than the eyenut itself.

Example of an eyenut

Australian Standard eyebolts must be collared. This is needed due to sideways pull.

AS2317 only lists working load limits for coarse metric thread eyebolts. But other thread types are allowed and mentioned in Australian Standards.

Take extreme care so that eyebolts are not screwed into threaded holes of a different size or thread type. Refer to mismatched threads and cross threading in AS2317.

Use of eyebolts and eyenuts

Only collared eyebolts should be used where the pull is inclined from the vertical. The underside of the eyebolt should be machined. The seating on which the eyebolt is tightened should also be machined.

The eyebolt should be tightened so that both faces meet in a neat tight fit. If both faces are apart the collar is of no use.

Any diagonal tension applied to an eyebolt should be in line. The pull should never be across the eye.

Do not insert a hook into an eyebolt. Always use a shackle, unless the eyebolt is large enough to accept a direct connection.

Where two eyebolts are used to lift a load, a pair of slings should be shackled into them. Do not reeve a single sling through two eyebolts and then put both eyes on the hook.

Use of eyebolts

Where eyebolts can't be kept in line with each other when tightened, insert a washer or shim without impeding the thread under the collars. This is to allow the eyebolts to be tightened when in line.

Do not tighten an eyebolt using a hammer. Use a podger bar. After tightening, check the "solid feeling" which indicates a properly fitted eyebolt.

Loads can spin when lifted with a single eyebolt. This can cause the eyebolt to unscrew from the load. Mouse the eyebolt to the load to stop unscrewing.

Eyebolts are often put on motors (or similar) to lift the casing off. It can be dangerous to lift loads with the eyebolts that are provided on the load. If no information is provided about an eyebolt lifting point, the load should be lifted with slings.

No de-ration is required when using Australian Standard or G100 eyebolts and eyenuts.