Rigging Shackles 101: Shackle Sizes And Shackle Materials

Rigging shackles can vary from different types, sizes, and qualities in order to suit different rigging jobs. That’s why when it comes to choosing the right type of shackles, one must have adequate knowledge about the basic properties it possesses.

This article will discuss some main properties of the shackles, as well as how those parameters are interconnected to each other.

Shackle sizes

No matter small shackles or big shackles, always be aware that the diameter of the shackle pin is usually longer than the shackle body measurements, however, the key measurements given under any standard shackle sizes will be the diameter of the shackle body, not the shackle pin sizes. Following the picture show how to measure shackle length:

how to measure shackle length

Due to varying shackle sizes, it might be clear that the shackle weights are different, normally, sizes or weights should not have more than a + or – 5% variance within standard shackle sizes(RR C 271 shackle, ASME b30 26 shackles), the most popular shackle sizes and dimensions currently available in the market are 3/4″, 5/8″, 1/2″, 1″, 3/8″ and  7/8″.

Shackle Material

Lifting shackles are made on the basis of loading capacity, performance, and environmental applications, These factors are firstly determined by the raw materials, normally they can be divided into three types of shackles by materials, they are carbon steel shackles(mild or low-carbon steel), alloy steel shackles and stainless steel shackles(inox steel or inox). If you want to know more about rigging hardware materials, check out this useful article.

Carbon Steel Shackles

Our conventional shackles, with safety factor of 6:1 or 4:1, hot dipped galvanized or galvanized finish. Available in round pin, screw pin, bolt type.

Alloy Steel Shackles

Alloy steel shackles feature improved mechanical properties, making them more highly loading limited, fatigues, or can be used in some extreme conditions. Safety Factor of 5:1. Refer our Grade 80 alloy steel shackles, It can achieve an equivalent WLL as carbon shackles in but with smaller and lighter weight design.

Stainless Steel Shackles

Stainless steel shackles feature a chromium oxide film on their surfaces which creates high corrosion resistance, can be used in saltwater or chemical environments, are ideal for marine applications. Shackles made from stainless steel are typically more expensive than galvanized shackles.

Both stainless steel shackles and galvanized shackles can offer protection from rust and corrosion, but stainless steel shackles are better choices, for the galvanised shackles just add a thin layer of zinc oxide on the shackle body, while stainless steel shackles are natural to protect against rust and corrosion because stainless steels contain the element “molybdenum”, which can be especially used in extreme conditions or moisture or in a high chloride environment.

Shackle sizes and material are part of the main aspects of rigging shackles that affect its grade & price. By having a rough idea of them, you may easily choose the right shackles but the best way of getting these figures is by asking your manufacturer in the first place.