End mills smaller than spec'd

[esolberg]

Another newbie questions.

On another thread some people suggested a problem I had may be due to my endmill being undersized so I got out my caliper and measured them all.

I have 8 different Onsrud mills ranging from 1/8" to 1/2" of various geometries. Every single one of them is under-sized. They tend to be about 0.006" under, but one of them is .05" under. I'm measuring across the widest part of the flutes (I'm basically putting the bit between the caliper jaws and slowly turning it so the flutes will expand the jaws to the fullest extent of the cutting edges). I also have a couple of YG1 mills and those are spot on 0.050".

Before I make any cuts with these measured diameters in my toolpaths, I thought I'd check with the experts here. Is there a chance these O-flute cutters are non symmetrical or off center or something, which would mean I can't measure the diameter this way. I suppose I could just cut some slots and measure those- probably a good idea regardless.

Thanks again for any input.

Eric

[sailfl]

Contact Onsrud and tell them your problem and see what they say. Give the manufature an opportunity to respond.

[jerry_stanek]

I get some bits that are stamped with the size on them like a .25 straight cut that is stamped .24. At where I work we always mic the bits as they are not always what they say they are this is Vortex, Onsrud, and Micro 100 bits.