3 Wire thread measurement

[eightball]

Thanks Tom, I hope you saw on one of the other forums that I am now cancer free. A colostimy is a small price to pay to see my granddaughter grow up. I posted once b4 a test shaft i made to make a #4 double lead left hand acme nut. Being a 1/2 inch lead i had to be very creative on how i held my wires. If i dropped them they went into the river. This was an automatic discharge valve that is literally over the edge of a river. I used o rings on the wires and a couple of rubber bands to hold a 1/4 tool steel over the top two wires to span the gap so i could mic over the wires.Fortunantly both threads were the same pitch diameter. I made the test piece about a thou bigger than the actual valve stem. the nut fit like a glove. I have made several ends for hydraulic cylinders at work measuring over wires held on by o rings. The other machinist at work borrow my test plugs all the time. Kinda funny when they used to laugh at me for making myself additional work. Guess i get the last laugh huh?