I can see trying to standardize on one collet system. I got started with 5C when I ordered a 5C chuck with my PM lathe. So as I added stuff it was 5C. I got started with a set of collets by 1/32s, not knowing the limitations of clamping range. Over time I've added some "by 64ths" and some square & hex. I now have: ER40 chuck, R8 to ER40 & collets by 1/32s. Permits me to cover what I can't with my 5C collets. Need to add 5c to ER40 adapter. I've seen them on eBay for $50>60. Little machine shop doesn't carry them.