.8125-16 UNJ-3A External Thread

[Butch1946]

I have an application that requires Cad Plating per QQ-P-416, Type II, Class 2. I have been getting different information about what my pre-plate Pitch Dia's should be manufactured to. My Post Plate Gages are Go Gage PD: .77719 & No Go PD: .76830. Looking up Calculating Pre Plate Screw Threads & Gages, I come up with the following.
Pre Plate Ring Gages: PD: .7671/.7699. Pre-Plate Ratios 60 Deg. Unified thread = 4:1. Using Pitch Micrometers to check. Hopefully someone can verify these numbers
Thanks in Advance for the help

 

[BillPSU]

You are going to have to do some testing by making various pitch diameter parts, identifying the parts and then plating the parts. Plating to a size requires data about the process and I can honestly say I have never made the thread you are calling out. You will have to do the work.

Good Luck
Bill