CO2 Laser Cutter Lenses;

For all CO2 laser cutters up to 180Watt tube power.

When the cutting quality or depth is degrading it may be one of few spares: Lenses, Mirrors, Tube or laser generator. Aside of course alignment of the laser beam.

Lenses comes in different "beam length". As a general rule the shorter the beam the less depth it has to cut deep sheets and elements but it's much finer for example for intricate engravings.

They come in inches or mm. For example as a standard most machine manufacturers supply 2" or 2.5" length which are 50 and 63mm. 

If you buying shorter lens you may remove from your laser head additional nut or extra section which extends nozzle position downwards for 2.5" or even 4" lenses.

As a general rule always measure from position of your lens in laser head down to material and "build up" your laser head to have nozzle just 5-6mm from the material.

When installing make sure the convex section of the lens (the curved outwards) is positioned to the laser beam - top of the head not towards the material. Material side has to be concave side.