How to Knurl on a Lathe

One of the more specialized cutting operations on the metal lathe is knurling. This operation creates a raised, formed surface, the purpose of which is to provide a grip surface with friction, a decorative surface, or a better interference fit. Whatever the purpose, the knurling operation is typically straight forward, provided you have the appropriate tools.

Things You'll Need

• Metal lathe
• Knurling tool holder
• Knurling tools
• Mild abrasive pad

Instructions

1. Set the lathe to a slow rotation speed. No matter what the material is, the speed of rotation should be set to a slower speed for the knurling operation.

2. Install the appropriate knurling tools. Depending upon the pattern desired, you will need to install either straight or angled knurling tool bits, with either a coarse, medium or fine spacing.

3. Make a first pass, applying the lightest possible pressure to the workpiece. You just want the knurling tools to barely touch the workpiece for the first pass. The idea is to see the faintest impression of the tool as it advances over the work piece. Depending upon if the pattern matches up, the spacing of the knurling tool bits and the carriage traverse speed may need to be adjusted.

4. Apply additional pressure, in successive passes, until the desired result is achieved. Once the desired pattern is achieved at the lowest pressure, increase the pressure in order to form the desired pattern. Take successively deeper passes until the desired end result is achieved.

5. Finish the surface with an abrasive pad. While turning at a slow speed, apply an abrasive pad by hand to clean up the surface, remove traces of the first trial passes, and remove any minor burrs from the knurled pattern.

Tips & Warnings

• Taking many passes with small increases in pressure is preferred to few passes with large steps, as it is easy to go too far and ruin a workpiece.

• Take all safety precautions whenever working with a power tool.

Resources

• Read this Article in Spanish