- Jacob arbor is the spindle to which the chuck is fastened.
- The arbor can be machined onto the end of a drill spindle or it can be a separate small part that can be removed from the drill.
- Arbors are small spindle shaped shanks that maybe tapered for use in MT style sockets on drill presses, or having plain round shanks for use in machine tools.
- Some cheaper drill presses require the chuck to be mounted directly to the spindle by either threading the chuck onto a threaded spindle end or to a JT taper.
- All Jacob arbor are precision machined and ground for maximum performance.