Description:Pinion shaft is used for the swing drive group that provides gear reduction between swing motor and swing gear, and method of holding upper portion of machine stationery in respect to lower portion of machine.Attributes:• Hardened steel shaft• Spur Gear Number of Teeth: 12• External Spline Number of Teeth: 42• Thread Size: M20Application:Consult your owner's manual or contact your local Cat Dealer for more information.