Knurling

Knurling tools are turning type tool that is used in the cutting tool industry to create patterns on metal. Here at Cromwell we stock a range of knurling tools from supplier JHL.

What are knurling tools?

Knurling tools are turning cutting tools that are designed to create a regular pattern on the surface of a part, usually metal, 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.

Why knurling tools?

Knurling tools create different designs that help to create greater friction when gripping the knurled part or tool and reduce slippage.

When knurling tools?

Knurling tools are used with lathes to generate a knurl pattern on a workpiece. A metal piece is held in a straight position on a lathe machine and the knurling tools is moved into the workpiece creating the pattern. Knurling tools are used in many applications and industries including automotive, industrial, aerospace, mechanical labs and more.

Types of knurling tools

There are a many different types of knurling tools available, each has its own features and benefits. To 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 two 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.

Considerations when choosing a knurling tool

• Knurl pattern/Style  -   There are various knurl pattern designs that create a different design. For example there are right-hand and left-hand diagonal knurls that each create a different pattern.
• Cut type  -   The desired depth of cut can be achieved by using various cut types: Medium, fine and coarse - all give a different overall finish.

FAQ

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.