CO2.
Some parts start out etching nicely for the first couple of characters, then we get burn thru, even in heavier gages (7ga). Some don't etch at all, some do very well.
"Outside of a dog, a book is a man's best friend. Inside a dog, it's too dark to read." - G. Marx
Are the parts all different? If so, do you run the same nest?
I've found that the thicker the part, the smaller the tab, although that frequently raises other problems.
Can you grain-constrain your parts? If they're long enough to span 3 slats, then they may not tip even if you don't tab them...
We cut parts from steel sheet, from 1mm to 12mm thick. We would like to etch these parts with a part number, and have had some success. The problem is that some parts etch well and others don't, in the same sheet. Using a ~2kw laser (Bystronics). In some cases, the etched number just fades out...
