What I thought too. Before I returned it, I made a few more mortises this morning and checked them with another batch of 6mm tenons. Even a sanded dry-fit tenon wouldn't remotely come close to being that loose.I would be very surprised if a CMT cutter is off.
This is sound advice. Being in a rather unique position, I have had Domino cutters sharpened (professionally)Make sure the depth is correct and the cutter is fully seated - the motion of the domino, even if the cutter isn't seated by 1 mm (0.040") could have drastic effects on hole width.
Also, if you install you can compare it against any other bit (except 4mm) for overall length - they should all be the same
Unlikely judging from the packaging/marking.Is it possible the cutter was a fake CMT? That kind of gap is pretty big really, hard to see how a CMT cutter could end up so out of spec?
My mistake, I glossed over your post with the feeler gauge.The other two settings would've resulted in much wider mortises. The critical issue was with the thickness of the mortises as the 0.127mm gap was way too much. A sheet of paper is 0.1mm thick.