How to Choose a Gear Cutter: Involute Gear Cutter Chart | Evolvent Design

Involute Gear Cutter Chart – How to Choose A Gear Cutter

Andrew Prestridge | March 8, 2022

Gear Cutter Sizes Explained

The involute gear cutter chart is designed to help you select the correct gear cutter based on the specifications of the gear you're trying to make. In short:

  • The Pitch (or module) of the gear and cutter need to match
  • The pressure angle of the gear and cutter need to match
  • The number of teeth in the gear need to fall within the range of the cutter (based on cutter number)

We've created a free involute gear cutter chart to select the right tooth count based on cutter number

The chart includes: tooth ranges for module cutters, tooth ranges for diametral pitch cutters, and even the tooth ranges for expanded "half-size" cutters

How to Choose a Gear Cutter

Involute gear cutters are a great option when you're looking to make a small number of gears or a replacement gear for one that's broken. Gear cutters work great in mills, and often times allow you to expand the capabilities of machines you already own.

To use an involute gear cutter effectively, you need to know the pitch (or module), pressure angle, and number of teeth of the gear you're trying to make. The cutter will be specific to the pitch and pressure angle, so they need to match exactly. Each gear cutter is also only suitable for cutting a range of tooth counts, and it takes eight different cutters to make every gear from 12 teeth to a rack ("infinite" teeth).

The numbering system is reversed between diametral pitch and module, so we recommend checking out our involute gear cutter chart to make sure your cutter will mill the gear you need.

Find, Compare, and Buy the Gear
Cutting Tools You Need to Mill Gears

Using an involute gear cutter to mill a gear

Gear Cutter Dimensions

While you need the right gear cutter to cut the gear you want, it's just as important to be able to hold onto the cutter. A typical gear cutter has a circular bore through its center, with a keyway. This lets the cutter run on a standard arbor in the spindle of your machine.

The other, typically less important, dimensions are the width and outer diameter (sometimes called "cutter diameter"). While literature provides a good reference, we recommend measuring these directly on the cutter you're looking to use to ensure the best quality gear.

Gear Cutter Size Chart

Pitch/Module and Pressure Angle need to match

Each cutter will only cut a specific pitch (module) and pressure angle

Cutter Number sets tooth count range

Each cutter can only cut gears within a narrow range of tooth counts

Cutter Numbers are reversed between metric and imperial

We made a chart to compare cutter number and tooth range for metric (module) and imperial (pitch) gears cutters

If you have a question and need help finding a cutter, whether it is in our store or not, please send us an e-mail to;


  • looks fantastic!

  • Gear

    Md roton
  • Thank you for the helpful information and the chart I am going to print it and place it in my shop for a quick reference.

    Randy Moore
  • Thanks for the interest and questions. Make sure and send us a note to for faster service.

    Andrew Prestridge
  • Great work ! Thank you.


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