Pinwheel

Pinwheel
Chain type	Extension

The pinwheel is a chain pattern that is a series of offset corner chains that form a compact spiral shape.

Unlike the staircase which otherwise has a similar construction and purpose, a pinwheel only needs extra bracing if the chain incorporates 4 chain links, in which case the first link must be prevented from disconnecting the last one. As each link in the pinwheel resembles the last link of a staircase, the bracing can be similarly provided by extending with a staircase, or with the sandwich to increase bulk.

A completed pinwheel has the benefit of cyclicity as long as there is proper bracing. This means it can potentially be set off from any of its constituent links. Compare and contrast with the loop chain type.