Laser Kerf measuring tool.

The Kerf of a laser is the width of the blade (laser beam) this varies between machines it changes depending on focus so it could be different for different material thicknesses.

*** Note :- added Feb 2015
The Kerf of the laser is reduced by reducing the power of the laser beam ***

I recently changed my focal lens orientation to be correct thanks to Spooky at the OPL laser forum. For some reason Chinese Laser cutters come with the focal lens upside down.. After researching this I found