All tools are not created equal

[RJSakowski]

I agree. Different mills can all have different length spindles and draw bars but the R-8 collets are an industry standard and should all have the same threads and thread depth. As well with R-8 tools. My Keyless chuck must also use a spacer

Actually, there is no industry standard for the R8 taper. It is an internal Bridgeport standard which has been held as propitiatory intellectual property.. Other manufacturers have reverse engineered Bridgeport tooling to derive their own internal standard. As a result, the can be minor variations in R8 tooling from different manufacturers. This has been painfully made aware in the past, particularly with Asian tooling. I ran into it years ago with Enco collets where some of them had a too shallow keyway which prevented the collet from seating properly

 

[ltlvt]

Actually, there is no industry standard for the R8 taper. It is an internal Bridgeport standard which has been held as propitiatory intellectual property.. Other manufacturers have reverse engineered Bridgeport tooling to derive their own internal standard. As a result, the can be minor variations in R8 tooling from different manufacturers. This has been painfully made aware in the past, particularly with Asian tooling. I ran into it years ago with Enco collets where some of them had a too shallow keyway which prevented the collet from seating properly

I will look for that. I have a set of imports that I have not used yet because of the spacer issue. Thanks for pointing it out.