Buy a Rego fix holder and compare the difference. The Mari will always be above a half thou and the Rego will always be below a half.Hey Milland. I should have mentioned that I have a brand new Maritool one-piece nut that I tried and that gave poor runout readings with a gage pin. I could compare it to my seized two-piece Alpstool nut to see if there is any difference.
Sometimes with just a simple reseating of the tool can achieve runout less than .0002 with a quality holder and collet.
I check small endmills runout before touch off. Low runout will always pay for itself with less dollars spent on premature tool wear.