Arbor

Arbor as a precision-machined, rotating shaft or mandrel used to support and drive cutting tools or grinding wheels. While it may appear as a simple spindle, the arbor is a critical component for maintaining axial alignment and concentricity in high-torque machining operations.

The Engineering Principle

An arbor functions as the primary interface between the machine’s spindle and the tool. It is designed to withstand significant bending and torsional stresses while ensuring that the tool rotates with sub-micron run-out. Typically, the arbor features a tapered end for secure mounting in the spindle and a keyed or threaded section to lock the tool in place.

Industrial Classifications

In industrial manufacturing, we categorize arbors based on their mounting and utility:

• Milling Arbors: Used in horizontal milling machines to hold gang cutters or saw blades.

• Expanding Arbors: Specialized mandrels that grip the internal diameter (ID) of a workpiece to allow for external machining.

• Slitting Arbors: Common in the tube and pipe industry, these hold the rotary slitting knives that cut steel coils into specific strip widths.