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.
Body piercing, a form of body modification, is the practice of puncturing or cutting a part of the human body, creating an opening in which jewellery may be worn.he needle is inserted into the body part being pierced, frequently by hand but sometimes with the aid of a needle holder or pusher. While the needle is still in the body, the initial jewellery to be worn in the piercing is pushed through the opening, following the back of the needle.