I bought a cheap 4" circular mini-saw to cut small PCB material. It does OK with the standard 40 tooth blade, but I wonder if a diamond blade would work better. Does anyone have actual experience using a diamond blade to cut FR4 material? Thanks.

 

I'm using this:

60 or 80 Tooth blade. (Forgot to check when I took the pic.) I think it's better with more teeth than diamond teeth.

 

The "harder" the cutting surface, the longer the blade will last. FR4 fibers are fairly abrasive and WILL wear down blades.. But we are talking LOTS of use for a circular saw blade.. Heck I've cut them with scissors a few times when needed. A metal shear will also work but can crush the fibers or cause joint cracking with SMT and through hole components if they are close to the cut edge.

Professionally they are routed with an end mill. Or V-scored with a bit and then separated with a depanelizer (basically a fancy pizza cutter).

 

I use a bandsaw with bimetal blade.

 

I use a giant pair of tin snips.

No dust, waste or hazard.