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Old 01-10-2010, 10:51 PM
VMFn542bob VMFn542bob is offline
Join Date: Oct 2009
Location: Arizona
Posts: 1,066

Originally Posted by HughUno View Post
To measure five-groove barrel use a 108 degree anvil micrometer. a three-groove barrel needs a 60 degree anvil micrometer.
Thanks for furthering my education. With a little research I have learned that the V-Anvil (Tri-Flu) Micrometer's primary purpose is for precision measurements of cylinders and fluted cutting tools. I've never had any problem measuring cylinders with conventional micrometers.
The most common cutters I encounter are 2 and 4 flute end mills which can easily be measured with any conventional micrometer or caliper.
The 3 flute (60 degrees) V-Anvil micrometer appears to be plentiful but expensive.
I have found reference to a 5 flute V-Anvil micrometer but it is also scarcer than chicken teeth.
The V-Anvil micrometer seems to me to be a very expensive and questionable way to make a simple groove diameter measurement on a soft lead slug. If you were to use one you would not want to use the pointed one you show. That one seems more appropriate for measuring the depth of a thread.
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