Acme thread measurement calculations

[Lanza]

I had a quick look at machinery's hand book on measuring acme thread over pins. I am familiar with V thread calculations and use them often. Could someone please post an example of the thread (127 mm) 5" Centralizing acme, (25.4 mm pitch) 1 tpi, pitch diameter (119.02) 4.6858" to (118.62) 4.670". I have metric drills available in 0.5mm as pins. I am not worried about lead angle affect from pin measurement (Is it much for this thread?)

 

[Heavey Metal]

remember to measure thread width also. gear tooth verner caliper.

 

[Conrad Hoffman]

If it's a 29 degree single-start, the best wire size is probably 13 mm. I get 5.29692 to 5.31269 inches over the wires using the Vogel formulas, but I'm half asleep so check the numbers! There's a calculator on my website here (7th item down) that you can fine tune things with.