Knurling tools are designed to create a regular pattern on the surface of a part, usually for grip but also for aesthetic purposes. They can be used to create straight and diagonal lined patterns or a criss-crossing combination to form a diamond shape, these designs help great greater friction when gripping the knurled part or tool, helping reduce slippage.

How do knurling tools work?

To create a knurled pattern on a workpiece, it is held in a lathe in a straight position. The lathe is then operated and once this happens the knurl holder is placed on the worktable. The tool is then moved towards the workpiece using a crank.

To generate a knurl pattern on a workpiece, a metal piece is held in a straight position on a lathe machine. When the lathe machine is switched on, a knurl holder is attached to the worktable. Knurl holders are used to hold knurling tools. Next, the knurling tool is moved forward toward the workpiece with a small crank.

Types of knurling tools

There are a few different types of knurling tools available, each has its own features and benefits. The help outline these Cromwell have provided examples of the most common types below.

Internal knurling holders - These are typically used for a bar style and for depth of knurl in the workpiece. The depth they cut to depends on the hardness of the material.

Standard - These knurl wheels also known as straight knurl wheels feature a sharp corner on the leading edge and are designed for heavy loading

Convex - Providing a precise finish these knurl wheels feature a sharp leading edge to help distribute load.

Bevelled - These knurl wheels have a blunt leading edge. This is to help distribute loading as the forces involved on the tool and holder are higher in order to displace material.

As well as the different tool types there are a number of patterns in which knurling tools are available:

Straight - These feature no helix angle and are used to create a straight knurled pattern.

Diagonal - These can face either left or right and feature a 30-degree helix angle for a diagonal knurled pattern

Diamond - There are tow types of diamond patterned knurl wheels, male and female. Female wheels are used to create a male (raised) diamond pattern on the workpiece, whereas male patterned knurl wheels are used to create recesses for the female pattern. They both typically feature a 30-degree helix angle.


What applications feature knurling?

Knurling is featured in many industries including automotive, industrial, and even aerospace. Weightlifting enthusiasts might recognise the patterns featuring on barbells, which were created using a knurling tool.