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How to Create a Knurl

You can find them all over a household: on dumbbell handles, knobs and other cylindrical household items. The geometrical patterns formed by knurling can be found in all types of devices where some texture or "grip" is needed on a smooth surface such as a screwdriver handle. By means of a knurling tool with rotating rollers and a lathe holding the workpiece in question, you are able to etch rather than cut a pattern onto the rounded surface. Small adjustments can form straight, angled or diamond-shaped knurls.

Things You'll Need

Knurling tool
Lathe
Cylindrical piece to be knurled
Lubricating oil
Steady blast of air
File
Wire brush

Instructions

- 1
  Take the distance between the teeth of the knurling tool and divide it by pi. Use a diameter that is a multiple of this relationship as a starting point and adjust this diameter as you machine a few practice knurls.
- 2
  Place the cylindrical item to be knurled into the lathe. Position the knurling tool perpendicular and center to the piece that will be knurled.
- 3
  Press the rollers of the knurling tool lightly into the piece to be machined. Rotate the spindle of the lathe so that the entire surface of the shaft twirls, coming into contact with the tool.
- 4
  Look for the repeated impressions on the workpiece to overlap with one another; if they do not, change the diameter. Machine off 0.0002 inch from the diameter at a time until you get subsequent rotations to produce aligned grooves. Keep that diameter for the remainder of the knurling.
- 5
  Feed the machine slowly along the length of the shaft. Make the first impression carefully so that subsequent impressions can become embedded onto it. Adjust the speed, feed and pressure as needed to form a deep enough impression.
- 6
  Stop and reverse the lathe if you wish to form a diamond pattern.
- 7
  Lubricate the knurling tool as you work to assist the grooves in overlapping. Blow air onto the surface of the cylinder as you work if you wish to reduce flyaway matter from sticking to the work as it is being machined.
- 8
  File away the sharp points on the finished knurl. Brush any flakes away with a wire brush.

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