Chain pins

Leaf Chain Pins

A key part of a leaf chain assembly is the chain anchor pin – sometimes called a clevis pin.  All FB leaf chain pins are made from a specially produced alloy steel which is heat-treated to increase surface hardness. Great care is taken to ensure that the core of the leaf chain pin remains malleable as this enables it to cope with repeated loads. The pin is also centrally polished to improve the surface finish and to achieve a tight tolerance on its diameter.

We believe the strongest possible connection is achieved when the leaf chain terminates on the inner links, fits internally to the leaf chain anchor and is held in place by a chain anchor pin. This method ensures the maximum number of sheer faces and the greatest tensile strength.  Using chain pins on the outer links of a leaf chain can have serious load carrying and safety issues. 

The diameter of the chain anchor pin is determined by the leaf chain it is anchoring. The length is dependent upon the design of the chain anchor – they can be manufactured to a wide variety of sizes and designs for the same type of leaf chain. We generally use three types of leaf chain anchor pins and connecting link. After the diameter, the next most important dimension is what we refer to as the “grip”. On a leaf chain with 2 split pin holes it’s the distance from inside to inside of the split pin holes.

Type B leaf chain pin

The most widely used chain pin type we refer to as type “B”  they have 2 holes in either end Split pins/Cotter pins they are the most cost effective for manufacture allow for removal from both sides but can be awkward to assemble on the machine.

Type A leaf chain pin

Often referred to as a top hat pin, we refer to this pin as type “A”.  They have one hole at the end for a split pin/cotter pin and a head which is larger than the leaf chain pin diameter.  The manufacturing process can be expensive as they require plunge grinding. They can only be removed from one side, can be useful where lateral space is limited and where concerns exist that the pin will snag on other components.


Type C leaf chain pin

We refer to this design as type “C”. They have 2 circlip grooves at each end. They can be useful where speed of assembly is important, where lateral space is limited and concerns exist that the pin will snag on other components

We hold a number of different pin lengths for each leaf chain size to ensure that the pins fit the chain anchor correctly.

You may find this article in our knowledge hub useful:

Leaf chain anchor bolts : key design consideration

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