Unlike the bottom stopper mounted on a closed end zipper, insertion pin, consisting of a box and pin mechanism, is located at the bottom end of the separating zipper.

Pins play a vital role in zipping up or down the zipper halves. Tiny as they are, these pins are available in various configurations. Here, we will discuss the classification of pins.

No technical degree is needed to learn about such pins. It is essential to have basic knowledge of these tiny pieces before buying if the zippers are not tailed to specific requirements.

Manufacturing material

Depending on the manufacturing material, pins have two types including zinc alloy pins and POM pins.

As the name suggest, zinc alloy pin is made of zinc alloy and is mainly used in metal or nylon zippers.

POM is the short name of Paraformaldehyde, which is used to manufacture the teeth of plastic zippers. POM pins are made from injection moulding and are mainly applicable in plastic zippers and nylon zippers. However, some of these pins are also applied to metal zippers. Nylon zippers with POM pins are also called as nylon zippers with plastic stoppers.


Pins are categorized into three types based on function.

One-way separating zippers: The location of the pin and box are on different sides of the zipper. This, in turn, will form a secure connection with the single slider passing on them.

Two-way separating zippers: Here, two pins are mounted on the zippers that actually contribute to the easy movements of sliders. These are often called mobile pin and fixing pin.

Easy release zippers: The pins vary from the regular pin structure. These zippers are normally used in sportswear as they provide the easy removal.

Handed version

Depending on the right or left location of the pin in the zipper, pins can be categorized into left sided pins and right sided pins.

If the inserted box is mounted on the right side then the pin will be placed on the left side and vice versa.

Use tips

One must ensure that the pin is inserted well into the box before moving the slider. If the box is not properly aligned with the pin, the slider will slide up only one side of the zipper tape while the other will remain stuck to it, resulting in improper functioning.