R8 or R8-ER20: which do I order?

Q: R8 or R8-ER20: which do I order?

Short answer: Order `R8-ER20` when you already know the shank size you run (1–13 mm). Order a bare R8 holder when you will change collet sizes between jobs. R8 shank, common on Bridgeport-type milling machines. Buying the assembled R8-ER20 saves matching a nut and collet yourself.

Question

Accepted Answer

Short answer: Order `R8-ER20` when you already know the shank size you run (1–13 mm). Order a bare R8 holder when you will change collet sizes between jobs.

R8 shank, common on Bridgeport-type milling machines. Buying the assembled R8-ER20 saves matching a nut and collet yourself.