What are Split Pins?

Engineered for accuracy and reliability, split pins—also known as cotter pins—are a mainstay in mechanical engineering. Designed to keep fasteners like nuts in their rightful place, these small yet incredibly efficient pins that split serve as a fastening system in applications requiring a moderate level of security. Whether you're securing the wheels on a vehicle or ensuring the stability of heavy machinery, combining a castle nut with a split pin can be indispensable in a variety of industries.

How To Use a Split Pin.

Understanding how to use a split pin is straightforward. Once a fastener, such as a castle nut, is in its correct position, the split pin is inserted into a perpendicular hole which aligns with the notches in the nut. Its two legs are then bent back or 'split,' providing a lock that restricts movement. The pin acts as a secondary securing element, offering additional assurance against the loosening or disengagement of primary fastening components. The result is a secure, yet easily removable, locking system.

What Material Split Pins Are Made From.

At Accu, our metal split pin fasteners are fabricated from premium A2 Stainless Steel and A4 Marine Grade Stainless Steel, ensuring maximum durability and corrosion resistance. 

For specific applications, we also offer black split pins through our AccuBlack service, these not only provide additional corrosion resistance, but the satin black finish aids in achieving an aesthetically pleasing look, especially when you want these components to blend in.

What Size and Type of Split Pins Are Available.

To suit the diverse requirements of your projects, our split pins range in size from as small as M1 (1mm) for delicate applications, to as large as M13 (13mm) for more robust engineering needs. The pins are also available in lengths from 4mm to 140mm giving you an incredibly varied range to choose from. Additionally, you have the option of A2 or A4 stainless steel split pins, catering to your specific material preferences.

FAQs.

Q: Is There a Specific Way for How To Install a Split Pin?.

A: To install a split pin, first you must install the fastening component into its correct position, taking care to align the holes for the split pin past the component it secures. Next, insert the pin legs through the hole (often through the threads) and bend them back around the component to lock the pin in place.

Q: How Does a Split Pin Work?.

A: A split pin works by inserting it into a perpendicular hole and then having its legs bent back to secure a fastener like a nut onto a threaded bolt. This pin acts as a blocker, making sure that a fastener cannot loosen past where the pin is stuck through as it essentially blocks the component from going any further along the threads.

Q: What Are Split Pins Used For?.

A: Split pins are commonly used to secure nuts, bolts, and other fastening components in machinery, automotive applications, and construction. They are a non-permanent engineering component that aids in stopping other fasteners from coming loose past a certain point along a thread.

To understand further uses of split pins, we have an article which explains why bolts become loose and what you can do to counteract it.

Q: Is a Split Pin the Same as a Cotter Pin?.

A: While terms are often used interchangeably, more so in the USA, there is no difference between a split pin and cotter pin. Functionally, they serve the same purpose and are used in the same scenarios.

Q: How Do You Remove a Split Pin?.

A: To remove a split pin, unbend the legs and pull the pin out. Some applications may require pliers for this task depending on how stiff or short the bent legs are.

Q: Are Split Pins Reusable?.

A: While it is possible, due to the stress imparted onto the legs when being bent, it is often recommended to use new split pins when old ones have been removed rather than attempting to re-use old pins.

Bespoke Split Pins Manufacture.

High precision, bespoke manufacture of Split Pins to customer specification. State of the art facilities specialising in both small batch prototyping and large scale manufacture.

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