15pcs ER11 Spring Collet Set for CNC Engraving Machine and Milling Lathe Tool Workholding Engraving Collets including 1mm-7mm,1/4",1/8"

Great for small collet enthusiasts that like to machine things at night. Can hold drill bits as well as mills and havent had much issue with runout .. all tool survive full RPM without crazy chatter.

Collet set is of good quality and I have used several of them on my CNC. Was a good purchase.

Fantastic collet set. First day I had them I used at least three different collets. I would give 5 stars but, one of them had a couple of pieces of metal chips inside from the slot cutting. I could not hesitate to buy them again, just know you'll want to check each one before the first use to make sure any metal chips do not interfere with the closer. I used the 3/8 to tram the head on a new mill. I then used the 1/4" to hold a indicator to square up my new vise and to mill the vise keys to fit my slots. I then use the 1/8 to mill a slot in a part. The results were perfection.

I used almost every one of these for a drill regrinding project, (1/8-1/2 by 1/32nds) and they all appeared concentric, gripped well, and gave drills with near perfect split points. (Perfect as far as I can measure.)I did not try to measure the accuracy of the holder, but if you are trying for sub 0.001" accuracy, I suspect that this should probably not be your set of choice.

Fast delivery quality parts. Would buy again.

These are collet-shaped objects. They are not collets.The product page has out-right lies on it. It claims 0.0005" accuracy. I measured the Total Indicator Runout (TIR) of a couple of these "collets" and found some to have as much as 0.0028" of runout. That's almost 3 thousandths of an inch of runout. Let me repeat that. Almost 3 thousandths of an inch of runout. Almost 6 times worse than what's claimed on the product page. Might be ok if you're drilling holes, but if you're milling steel with an end mill this is unacceptable (even for a hobby-machinist).They have random gouges on them (from the "machining" process by which they were manufactured). The vertical slits are filled with burs that span the entire width of the gap (preventing them from compressing like an actual collet would).It appears that someone was practicing or learning how to make collets and decided it was ok (it's not) to sell their mistakes on Amazon. This company should be ashamed of themselves, and this product should be delisted from Amazon.A complete waste of your time. DO NOT BUY.

Was a bit skeptical about the quality for such a competitive price - was mostly concerned about the runout. Have to say I was VERY pleasantly surprised. Using 0.001 indicator, measured the runout on 2 randomly selected collets. Runout was virtually imperceptible. Would need a .0005 or .0001 indicator to give a specific reading.The only negative is the etching of the sizes on some of the collets - not very deep, a bit off-center and some were pretty small. Not an issue for me now as I quickly built a simple plywood holder to keep them organized.

Everything was great they look great