Anchor and D-Ring Lifting Shackles
Heavy duty rigging shackles are used every day in the material handling industry to connect lifting slings, wire rope, chain, and fiber rope either to a load or to each other. Shackles are extremely versatile and come in a variety of designs and constructions, as well as a variety of different materials. This makes shackles versatile in both design and use. Rigging and lifting shackles can be used for:
- Towing or pulling
Different combinations of designs and materials will make certain lifting shackles better suited to different lifting applications. This makes choosing the correct shackle for your lifting application difficult. Below we will go over the different styles and materials used to construct lifting shackles and how they perform compared to each other. If you are unable to find what you are looking for, or if you don’t know exactly what you need, feel free to call or email our sales team to speak with a rigging product specialist.
Types of Shackles
No matter what type, all lifting shackles are comprised of the same 4 parts:
- Bow: the curved part of the shackle body opposite the pin, sometimes referred to as the bail, body, dee, or bowl
- Ears: the parts of the shackle body that support the shackle pin
- Pin: a steel bolt made to span the two shackle ears
- Shoulder: the portion of the pin that is in contact with the ear of the shackle when the pin is fully threaded or engaged
The types of shackles differ in three basic ways:
- Style of Body / Bow
- Anchor / Bow
- Chain / D Ring
- Style of Pin
- Screw Pin
- Bolt, Nut and Cotter
- Round Pin
- Alloy Steel
- Carbon Steel
- Super Strong Carbon Steel
- Galvanized Steel
- Stainless Steel
Note: These shackle materials only apply to the body of the shackle. All shackle pins are made of alloy steel.
In order to perform a safe lift, you must choose the shackle with the correct body style, pin style and material for the job. Lacking one of these three criteria can put your load and/or workers in jeopardy.
Shackle Body Styles
The two most common body styles are anchor shackles, sometimes referred to as bow shackles, and chain shackles, sometimes referred to as D shackles. Any other body style would be considered a specialty shackle, which we will touch on further down.
Anchor and Bow Shackles
These crane shackles are called anchor or bow shackles due to their large “O” shaped bow. This bow design gives them the ability to be used in multi sling configurations as well as the ability to be side loaded (with some reduction in working load limit). Although the term bow and anchor shackle are used interchangeably, a true bow shackle has a larger and more defined “O” shaped bow than an anchor shackle.
Chain and D Shackles
These crane shackles are called chain or D shackles because of their “D” shaped bow. Chain shackles have narrower bows than anchor and bow shackles. This bow design gives D shackles the ability to carry extremely heavy loads in an in-line position. Unlike anchor and bow shackles, chain and D shackles should never be side loaded, as they are designed and rated for in-line tension only.
Shackle Pin Styles
Lifting shackles of all body types are available in three basic pin designs:
- Screw Pin Shackles
- Bolt Type Shackles
- Round Pin Shackles
Screw Pin Shackles
Screw pin shackles are secured by inserting a threaded pin through the non-threaded ear of the shackle and tightening the pin by hand through the threaded ear. These lifting shackles are perfect for applications where the shackle is frequently removed and in “pick and place” applications where slings and rigging hardware are changed out often.
It is very important to always tighten the screw pin before each lift because depending on the lifting application, your screw pin may be rotated or twisted out of the threads during the lift. To combat this, you might even consider mousing the pin to the shackle body in semi-permanent applications to prevent the pin from rotating. Mousing is achieved by looping annealed iron wire through the hole in the collar of the pin and around the leg of the shackle. The wires are then tightly twisted together to secure the pin to the shackle body. Whenever you use a screw pin shackle, the rigger should make sure the threads are fully engaged, tight, and the shoulder is in contact with the body of the shackle before attempting any lift.
Bolt Type Shackles
Bolt type shackles, sometimes referred to as bolt and nut cotter shackles or safety shackles are lifting shackles with a pin that is secured using a bolt, nut and cotter. They are called safety shackles because they offer industry leading safety and securement when it comes to lifting shackles. A bolt type shackle design is more secure than a screw pin shackle and is therefore extremely well suited for more permanent applications, as well as applications where the shackle is expected to experience twisting or rotating. The nut and cotter design also removes the need to tighten the shackle pin before every lift. Safety shackles are well suited for almost any lifting application; however, they are not as easy to remove as screw pin or round pin shackles. Bolt type shackles are available in DNV Type Certified versions which are perfect for offshore, saltwater and more broad marine applications.
Round Pin Shackles
Round pin shackles are constructed using a round, unthreaded pin that is secured by a cotter. Round pin shackles are ideal for applications where the shackle may be subjected to twisting or torquing, since rotating motions cannot dislodge the pin. Round pin shackles are not as secure as bolt or screw pin type shackles and are therefore not to be used for overhead lifting. They are also not to be used as a collector ring for multi-leg sling rigging applications. Round pin shackles are most commonly used in tie-down, towing, and suspension applications.
While the shackle types above are very versatile and are suitable for most lifting applications, specialty shackles are sometimes required to make a safe and secure lift. These more specialized shackles include but are not limited to:
- Synthetic Sling Shackles
- Wide Body Shackles
- Long Reach Shackles
- Stainless Steel Shackles
- Sheet Pile Shackles
Synthetic Sling Shackles
Synthetic slings require special shackles because they tend to pinch and bunch in regular shackles. This bunching and pinching can severely reduce a synthetic sling’s working load limit. Synthetic sling shackles have an extra wide and flat bow which increases the bearing surface on the bow and sling. This higher surface contact area allows the synthetic sling to be used at 100% of its rated capacity, with no danger of damaging the sling.
Wide Body Shackles
Wide body shackles have a standard “O” shaped bow that is even bigger and wider than traditional anchor shackles. Wide body shackles are useful for rigging synthetic round and web slings and especially for rigging wire rope slings. Shackles used in wire rope sling rigging must have a diameter that is greater than or equal to the diameter of the wire rope. This is called the D/d ratio. Wide body shackles allow you to rig large wire ropes that require a larger diameter shackle to reach the needed D/d ratio. Having the proper D/d ratio allows slings to have a longer service life and eliminates the need for a thimble eye in wire rope slings.
Long Reach Shackles
Long reach shackles are ideal for applications in the construction industry where a longer reach is needed to attach to pick points. Just like D ring shackles, long reach shackles should never be side or point loaded. To achieve the full working load limit, the load should be evenly distributed over the entire pin. Long reach shackles can additionally be used as a bail for lifting thicker objects.
Sheet Pile Shackles
Sheet pile shackles are made specifically for pulling sheet piling. They are equipped with a with an easy opening pin which does not detach from the shackle. While sheet pile shackles are limited in their scope of use, they perform their specific job extraordinarily well.
The material a shackle is made of is an important consideration when it comes to choosing the correct rigging shackle for your lifting application. Rigging shackles come in five different types of materials, all having their own set of benefits and drawbacks:
- Alloy Steel Shackles
- Carbon Steel Shackles
- Super Strong Carbon Steel Shackles
- Galvanized Steel Shackles
- Stainless Steel Shackles
The material a shackle is made from only pertains to the body of the shackle. All shackle pins are made from alloy steel.
Alloy Steel Shackles
Alloy steel shackles come with a design factor of 5:1. They are stronger than carbon steel and therefore have a higher working load limit than carbon steel shackles of the same size. Alloy steel shackles are more expensive than carbon steel shackles but are popular for their strong and lightweight design. Alloy steel shackles are available in screw pin, bolt type and round pin configurations.
Carbon Steel Shackles
Carbon steel shackles come with a design factor of 5:1. While they are not as strong as alloy steel shackles, they are much more economical. Carbon steel shackles are perfect for applications where the size of the shackle does not matter just so long as it lifts the required load. These shackles are available in screw pin, bolt type and round pin configurations.
Super Strong Carbon Steel
Offered only by Columbus McKinnon, super strong carbon steel is the perfect combination of the strength and size benefits of the alloy steel with the economic benefits of the carbon steel. CM super strong carbon steel shackles come with a design factor of 6:1. Just like the alloy steel, super strong carbon steel shackles can achieve the same working load limit with a smaller diameter design than the regular carbon steel shackles. Furthermore, like the carbon steel, CM super strong carbon steel shackles can lift the same working load limit as alloy steel shackles, at a fraction of the price. Super strong carbon steel shackles are ideal for any lifting application in which regular carbon steel or alloy steel shackles would be used. Super strong carbon steel shackles are available in screw pin, bolt type and round pin configurations.
Galvanized and Stainless-Steel Shackles
Galvanized and stainless steel shackles are both ideal for corrosive environments. Galvanized steel shackles are coated with a layer of zinc which protects them from corrosion. This gives them the ability to be used in corrosive industrial applications where moisture is not an issue.
If moisture is an issue, stainless steel shackles are the perfect solution. Stainless steel shackles are extremely popular in the marine industry due to their industry leading corrosion resistance. Stainless steel shackles are, however, more expensive than galvanized steel shackles.
Galvanized and stainless steel shackles are available in screw pin, bolt type and round pin configurations.
Tri-State Rigging Equipment is a service provider and distributor for all industrial crane shackles for rigging and lifting serving clients from coast to coast, Canada, Mexico and especially focused in the states of Missouri, Illinois, Indiana, Iowa, Kansas, Nebraska, Arkansas, Mississippi, Tennessee, Kentucky, South Carolina, Florida, and Oklahoma.