In this article about cotter pins, we’ll cover details like what a cotter pin is, what it’s used for, where it’s used, cotter pin material, dimensions and standards, and cotter pin drawings.
What Is a Cotter Pin?
A cotter pin (also called a split pin) is a standard machine element generally used, especially in machines subject to vibration, to prevent nuts, dowel pins, and adjustment collars from loosening on their own.
Cotter pins are shaped like a forceps. Both ends of the cotter pin are inserted into a hole, and the two ends are then bent in different directions to secure it. The cotter pin’s diameter must be smaller than the hole it will be fitted into. However, a cotter pin’s nominal diameter is named based on the size of the hole it will be fitted into.
Safety Pin Function
A cotter pin is a simple safety pin that prevents elements like a castellated nut from loosening and rotating under vibration.
Single-Use Construction
A removed cotter pin has been bent and cannot be safely reused — it must be replaced with a new one.
Standard Diameter Range
Depending on the application, cotter pins are generally manufactured in diameters ranging from 1 mm to 20 mm.
What Does a Cotter Pin Do
A cotter pin is one of the simple solutions used to prevent fasteners operating in vibrating environments from coming loose on their own and creating a safety problem. It’s sometimes also used as a fastener on its own.
Where Is a Cotter Pin Used?
An example of a cotter pin being used as a safety element. (left) Here, the cotter pin’s role is to prevent the nut from loosening and coming undone on its own in vibrating environments. In the example, a castellated nut is used.
In the photo above, we can see a cotter pin used on an automobile’s brake disc.
In the image above, we see a cotter pin used on the propeller of a fishing boat’s engine.
Above, we see cotter pins used in a roller chain. This joint could also have been made with a rivet. However, if easy disassembly and reassembly is your goal, a cotter pin can be preferred.
As another example of where cotter pins are used, in this photo we see a cotter pin securing a nut on a load-lifting ring.
In this article, we covered what a machine part known as a cotter pin or split pin does, and where it’s used. Until we meet again in new articles.
Related Questions
For the cotter pin to fit through the hole comfortably, its physical diameter needs to be slightly smaller than the hole. This is why the product is named based on the standard size of the hole it will be used in, rather than its own exact diameter.
Vibration can cause elements like nuts to gradually loosen and rotate on their own. A bent cotter pin physically blocks this rotational movement, keeping the connection fixed even under vibration.
Related Posts
