Knurling Tools Operation and Maintenance Guide
Knurling tools create a textured pattern on cylindrical workpiece surfaces for improved grip, aesthetics, or dimensional increase for press fits.
I. Knurling Patterns
- Straight Knurl: Parallel ridges along the workpiece axis for improved grip in axial loading
- Diamond Knurl: Cross-hatched pattern for improved grip in all directions, the most common knurling pattern
- Diagonal Knurl: Angled ridges for specific gripping or decorative applications
II. Setup and Operation
- Workpiece Diameter: The workpiece diameter should be an exact multiple of the knurl pitch for clean pattern formation. Adjust diameter if tracking issues occur.
- Tool Position: Set the knurling tool precisely on center height and perpendicular to the workpiece.
- Feed Engagement: Engage the knurls quickly and firmly into the workpiece. Hesitant engagement produces double-tracking.
- Coolant: Apply generous coolant during knurling. The process generates significant heat and pressure.
- Speed: Use slow spindle speed, typically one hundred to three hundred RPM, with moderate feed rate.
III. Maintenance
- Inspect knurl wheels for wear, flat spots, or damaged teeth
- Clean and lubricate the knurl wheel bearings regularly
- Replace knurl wheels when the pattern quality degrades
- Check the tool body for cracks from the high forming forces involved
