PSA: Don't trust brand new ER collets out of the box

I run a small shop outside Cleveland and last Tuesday I threw a fresh set of ER32 collets into my holder for a 1/2 inch end mill. First part came out with .004 runout, which I thought was just a dirty taper so I cleaned everything twice. Still .004, so I grabbed my old beater collet from the bottom of the drawer and instantly got .0005. Turned out the new ones had a burr on the internal taper from the factory, nothing visible without a loop. I spent two hours chasing a tolerance issue that was never my machine's fault. Now I check every new collet with a test bar before it goes near a job. Has anyone else had a bad batch from a reputable brand lately, or am I just lucky?

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jason_stone121mo ago

Stop taking anything at face value these days. I bought a brand new torque wrench last month, clicked it against my old calibrated one on the same bolt, and it was off by 15 percent right out of the plastic. Same story with a digital caliper I got for Christmas, zeroed fine but drifted a full thou halfway through measuring a block. It's like nobody does final inspection anymore, they just box it up and ship it. Your collet story is just another version of that same lazy QC virus we're all dealing with. Good on you for catching it before it ruined a paying job, I'm about to start checking every new tool the same way you do.

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