Using Tormach bit 34681 .125 engraving bit to make keychains with my students. After dulling the end of one of the bits already I am wondering what everyone is running for depth of cut and feeds and speeds for this bit.

Unlikely you “dulled” the end. More likely the tip broke off. Let us know: Which machine? What material? Coolant? This type of engraving cutter is probably best suited to high rpm shallow DOC and soft material.

Correct, I did snap the end off of the bit. I am using a Tormach 1100. We are machining aluminum with coolant.

give it all the rpms, maybe .0003-.0005" ipt feed .002-.005" DOC? I don’t run that style engraver anymore so I can’t offer a proven recipe.

Those engraver bits break very easily. I changed to chamfer mills after breaking 3 engravers on one part. Chamfer mills are about the same price more flutes and a lot tougher.