This chain is for a pinion gear drive that uses an attachment chain and special sprocket instead of a rack and pinion gear. Wrap the chain around the inner/outer circumference of a drum and bolt the attachments to install, or install linearly. Use a heat treated bolt for attachment. Requires a special sprocket. For linear drive and large radius rotary drives, a chain gear drive is used by a drive source (motor, etc.) through a reducer. Chains require a lot of space, and gears need precision machining, which can lead to high costs and other issues. Pin Gears are perfect in these situations. An attachment chain is wound around the outside of a drum in place of a gear drive wheel, and a specially machined sprocket is used for the pinion gear. For linear drives, the attachment chain is attached linearly and used in place of a rack.