Advice on Engraving Cutters

[StevenB]

I use U-Marq's CARBIDE CUTTERS in my engraving machines, which are fine for most jobs.

When engraving slate however,they just won't keep their edge.

Is there a more robust cutter out there on the market, or anything else I should know about how to engrave slate in order to get the job done properly?

 

I see PANTOGRAPH SERVICES have three different types of cutter listed on their website, should I be trying one of these instead?

 

As ever, all advice welcomed.