A lathe travelling steady, also known as a steady rest or centre rest, is a tool used in metalworking to support and stabilize long and slender workpieces during turning operations.

The purpose of a lathe travelling steady is to prevent the workpiece from flexing, bending or vibrating while it is being turned on the lathe. This is particularly important when machining long workpieces with a small diameter, such as shafts, pipes, or rods.

When a workpiece is turned on a lathe, the cutting forces generated by the cutting tool can cause the workpiece to bend or vibrate, which can result in a poor surface finish, inaccurate dimensions, or even damage to the workpiece or lathe. The travelling steady supports the workpiece at a point closer to the cutting tool, reducing the risk of deflection or vibration.

The travelling steady consists of a support shoe, which contacts the workpiece, and two adjustable jaws that hold the workpiece in place. The shoe is mounted on a sliding carriage that moves along the bed of the lathe, allowing it to be positioned at different points along the length of the workpiece.