Ho do you measure end mill diameters?

[antsals]

Just found one...... http://www.mitutoyo.co.uk/MitProd/mt...1!Opendocument but taking a cut in material is also an option I have in the past input the size around nominal knowing the cutter is bigger so dependant what you are doing eg inside slot or outside it would leave metal on the component all over. Then check how bit it all is and adjust the offset accordingly. It means you get a good component first time.

Ant

[AdieR]

2.00mm EM reading 1.86mm?

Not sure what cutters you're measuring (3 or 4 flute), or what you're measuring with (calipers or mic), but one point I'll mention is that it is easy to overdo pressure on your measuring tool (ie pushing a caliper too far or tightening a mic too far) and giving a false reading. I have seen people (even in the trade) tighten mic's like g-clamps (not good, because it twists the frame).

If its a 4-flute, slide it until caliper jaws *just* touch, and rotate it until you get the highest reading - this is your actual size.

You say the cutters are from ebay - in which case they may be worn anyway (not knowing how they've been used / treated).

One other point of note: re-ground cutters can sometimes cut slightly oversize.