Welcome to the new Ronstan Industrial website!

Sister Clips, Brummel Hooks, and Inglefield Clips


Ask three people what they call this piece of hardware, and you might get three different answers. The truth is the terms sister clip, Brummel hook, and Inglefield clip are interchangeable and all refer to the simple interlocking clips pictured below.

These clips can be easily connected or disconnected by carefully aligning the side openings of two clips by hand. When pulled tight, the sister clips are securely fastened. With no complex or moving parts, sister clips have remained essentially unchanged in design since their invention, and they remain a popular choice today due to their simple reliability and ease of use.

Sister clips were invented in the 1890s by Lieutenant Edward Fitzmaurice Inglefield of the Royal British Navy. Their original purpose, quickly and easily connecting a flag to a halyard, is still one of their most common uses today. By 1895 these clips were standard issue to the Royal British Navy.

What type of sister clips are there?

Conceptually, sister clips all look similar and function in the same basic manner. One of the most significant ways they differ is their material. Today, they are commonly made from hard plastics to be strong, light, and durable. They can also come in other materials such as bronze, brass, or stainless steel, which while heavier than plastic can be stronger and more aesthetically pleasing.

Another common variation of a sister clip involves adding a swivel to the end that attaches to the material (the non-linking end). Allowing this component to swivel or rotate can prevent unwanted twisting in the system. For example, if the swivel side is attached to a flag halyard, it can allow the rope to twist without twisting or influencing the flag itself.


Sister clips are used for dozens of applications beyond raising and lowering flags on boats and buildings. As one of the simplest methods of connecting two pieces of rope, they are also sometimes used on a small sailboat’s spinnaker sheets, jib sheets, and hull covers. Off the water, sister clips can be found on various bits of camping and outdoor equipment, key chains, backpacks, and more.

men cleaning the windows of a high rise building