A shackle is an essential component of many rigging systems. Also known as a gyve, it consists of a U-shaped piece of metal with an opening at the end. You can secure a shackle by placing a bolt or pin through this opening. While most shackles use this same design, however, they are available in different styles.
Material
Shackles are available in different materials. Some of them are made of advanced microalloy, whereas others are made of tempered carbon. Microalloy and carbon are both strong materials, making them an excellent choice for rigging components like shackles.
Finish
In addition to the material, you should consider the finish when choosing a shackle. Some shackles feature a painted finish. They have an outer layer of paint that shields and protects the underlying base material from they are made. Other shackles feature a galvanized finish. Galvanization involves the application of a protective layer, typically by dipping the object in molten zinc.
Pin or No Pin
You should check to see whether or not the shackle comes with a pin. Without a pin, you won’t be able to use the shackle. The pin will close the shackle so that you can secure loads to it. While some shackles come with a pin, though, others don’t. If the shackle doesn’t come with a pin, you’ll have to purchase a pin separately.
Size
Not all shackles are the same size. Shackles, as well as the pins with which they are used, are available in many different sizes. Some of them are longer and have a wider opening than others. Larger shackles can typically support more weight (see below), but they also require larger pins. Nonetheless, you should consider the size when choosing a shackle.
Working Load Limit
One of the most important things to consider when choosing a shackle is the working load limit. This represents the maximum weight a shackle can safely support. The working load limit of a shackle can range from 0.75 tons to over 10 tons. Think about how you intend to use the shackle and choose a working load limit that can withstand the weight of the loads.
Testing
You can order shackles with special testing. Fatigue testing, for instance, is available upon request. During fatigue testing, the shackle will be exposed to measurable stress to determine whether permanent structural changes will occur. Proof load and magnetic particle testing is also available upon request.