[Bob Shaw]

I had a look at Toms thread. He is using a milling/grinding cutter. Good results but not what you're doing.

I'm surprised your diamonds are wearing out on glass.

What I am concerned with is not the wear while they're being dragged, but the impact when you raise & lower them.

If you lift & drop too fast you will chip the diamond which will cause it to wear out prematurely.

Have you considered carbide tips? I think for you they may last as long as your diamonds do now and they are USD 3 each from this guy:

www.dragengraving.com

Worth a try if you're paying USD 20 for diamond tips.

Thanks,

Bob.

[Thyme]

Thanks Bob, I will take a look at those.
I hadn't considered impact, and where I am engraving a narrow area there is a lot of raising and lowering.