Cut Circles Accurately With
A Glass Circle Cutter

Cutting circles in fusing glass is best done by using a tool  specially designed to make circle cutting easy.

There are a variety of cutters available that will assist you to cut circles accurately.

Follow the makers’ instructions for the correct operation of the glass cutter.

As with all other cuts this operation is done in two steps, score the glass and then snap the glass.


Clean the glass properly. Ensure that glass diameter is about 5/8” larger than the diameter of the circle.

If using a suction cup cutter you can use a felt tip pen to draw diagonal lines from the corners, you will be able to match up the lines on the suction cup to ensure that the tool is centered.

Adjust the cutting head to the desired diameter.

You will need to ensure that all obstructions around the work area are removed to ensure that the rod can rotate freely.

The cutting wheel must be lubricated prior to cutting. Pour a small amount of cutting oil onto a paper towel and wipe the towel across the wheel. A small brush dipped in oil will do the same thing.

Scoring The Glass

Make sure you are wearing your safety glasses; small fragments of glass can break away during any glass cutting operation.

Rotate the tool in a smooth uninterrupted motion until the score is completed.

Do not rush through the score, if the glass is not smooth, cut slowly so that the score is completed around the glass.

Turn the glass over onto a padded surface such as a carpet square and begin to gently press down on the score line with your thumb all the way round.

You press down, lift your thumb and press further around.

Do not use too much pressure as the glass may break.

Some people prefer to use the heel of their hand for this stage.

Once you have run the score turn the glass over again carefully, holding the circle to ensure it doesn’t fall out.

In order to break the circle out you will need to make relief scores from the circle out to the corners of the glass with your normal glass cutter.

Do not cut through the circle score line.

Once you have run the relief scores gently tapping along the score lines will result in the scores running and they should fall gently away.

You may need more than one relief line per corner subject to the glass size.

Straight Relief Lines

You can also score your straight lines at 3,6,9 and 12 o’clock.

The score lines should start just outside the circle score to prevent the glass breaking across the circle.

Turn the glass over and run the score by pressing the heel of your hand at the 2,4,6,8 and 10’clock position.

Once you have run the score completely, press down on the straight relief lines. If your scores have run properly then the four sides should come off without the need to use pliers.

If you wish to make a glass ring from your cut circle, say 1/2” wide. Position your cutter and set the inner diameter.

Run the cutter around to complete the cut.

Turn the glass over on a padded surface and go around the score with you thumb or heel of your hand until it has run. If it does not run do not use extra pressure, you may need to repeat this a number of times.

Turn the glass over, run one straight relief score just back from the center score line, turn the glass over again and press down on the line until it runs. The center should come away and you will be left with a glass ring.

Circle cutting requires patience and practice to perfect.

The ability to cut circles will enhance your glass fusing skills as well as enabling you to carry out a wider range of projects.

I have included a video, which will take you through the cutting process; it will show you how to use running pliers to break the edge pieces away.

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