This question is about my 2mm ER20 collet.
When I first started milling, I had no problems with breaking my 2mm bits. I cut heaps of stuff.
I was doing cuts through hardwood ply at around 12000rpm depth of about 3.5mm (approx 1/8 inch) and feed speed of 300mm/minute (12inch/min)
and all was well.
One day I was milling and I pushed the envelope too far and snapped the bit. Which in turn, damaged the collet a very small amount. It doesn't have that nice square opening anymore, although it doesn't really look all that bad. Since then, I have been snapping bits like crazy!
I am now getting a bit suspisious about the collet.
Do you think that it could be the culprit with regards to snapping my 2mm bits?
It is possible but unlikely. Is your collet pricey? If not replace it and test at normal feeds and speeds. Please post picture of damaged piece.