Our lasers focus a beam of light to cut through materials and the amount of material that the laser burns away is known as Kerf.
Material specific average kerf sizes are listed on our materials pages under technical specifications.
With the exception of our laser cut metals, the head of the laser directly follows the paths in your design file, meaning the Kerf is centered on these lines.
The dimension of the Kerf starts at about 0.2mm and varies depending on both your material and your design:
- The thicker and/or harder a material, the longer it takes to cut all the way through and the bigger the Kerf is going to be. Materials with low melting points will also have a larger kerf (eg styrene).
- Natural materials (eg wood) aren't always completely flat, meaning that the laser may not be perfectly focused in parts giving you a wider Kerf in sections
- The laser cuts curved lines slower than straight lines, therefore the Kerf is bigger on curved paths
Designing to allow for kerf
If you are using one our our laser cut metals, you do not need to compensate for kerf in your design. Our metal laser cutting machines auto offset lines to compensate for kerf.
For all our other materials, you will want to consider kerf in your design setup.
Let's say you were making two parts to fit together. One a white acrylic square and one a red acrylic hollow square to go around it. These materials both have an average kerf of 0.2mm.
If you were to draw the square and hole at 40mm, the white square on the right would end up around 39.80mm and the hole in the middle of the red square would be around 40.20mm. The fit would be loose on these parts.
However if they are dimensioned the square at 40.2mm and the hole at 39.8mm to allow for the laser burning material away, both the hole and the white square will come out closer to 40mm and they should fit more snugly together.
If you are creating a new design, it's always best to prototype a few variations of sizes to find the best fit, before producing a larger run on parts. Kerf values listed on the site are averages, so the dimensions can vary a little from this.