EDIT : Apologies, I was expecting depth to be (major-major)/2. But the thread depth was calculating the full required cut to give the thread profile. Original message: Hi, I'm using standard definition for an M12x1.5 thread. I'm then pushing it through a modified post LX3 processor for my XYZ proturn 350 lathe. I use a G138 cycle which is populated by the post. My issue is, the lathe likes a simple major / minor. The major I could calculate with the following code to remove any first pass data: this.major = x + getParameter("operation:firstPassDepth"); The minor I have tried and tried again to get to, as far as I can tell, it should just be major - minor / 2. For M12x1.5 I make this (11.85-10.137) / 2 = 0.8565mm. Yet if I interrogate getParameter("operation:threadDepth");  I get 1.11mm? Thanks, Alex.