Any recommendations on excellent quality collets.
Teknics are the way to go.
Does the brand of nut make a difference
Precise bits - Thinkandtinker.com
Personally, if you want the very best, Rego-Fix is the way I’d send you. They are a Swiss company who invented the ER collet. The only other company who compares technically is a company called BIG Daishowa Seiki out of Japan. Be prepared to pay for the quality, however! But you definitely get what you pay for. The real caveat is whether your spindle runout is good enough to take advantage of .0001” or better runout (measured at 4x diameter of the nose of the collet).
And yes, nuts make a huge difference in runout and transferable clamping force efficiency.
Both companies have US offices and sell through machine tool and cutting tool distributors for the metalworking industry.
I am running the Hiteco 8.7 from AVID, probably not a worthy spindle of the .0001" runout. With that said though I have had clamping issues where the down cut end mill got put out of the collet. I am not a professional so it could have been user error.
Understandable. May sure your putting enough elbow grease in the wrench when you tighten.