Measuring a bicycle chain's pitch can be used to identify chain wear and flag the need for a replacement chain and/or cogs and chainrings. Bicycle Chains: Length, Width, What's Best to Buy etc.
An industrial, or scaffold, piercing is made up of two holes that are connected by a single piece of jewelry (usually a long barbell). An industrial piercing is commonly made through the cartilage on the upper ear, with one hole close to the head and the other further down on the outer rim. Two or more industrials on one ear is sometimes referred to as an ear cage.
What is Dermal Piercing? Dermal piercings, also known as microdermal piercings or single-point piercings, are piercings installed on flat surfaces of the body. Dermal piercings are different from ordinary body piercings in that the latter have entry and exit points for the jewelry. In dermal piercing, only one end of the ornament emerges from the surface of the skin; the other end is embedded in the dermal layer of the skin.