To properly cut an odd numbered thread with a lathe using the thread dial indicator illustrated, you should close the lathe split, or half-nut on __________. Illustration GS-0084

Correct Answer: Option A — any numbered line on the dial

For odd-numbered threads, the lead screw pitch is not an even multiple of the thread pitch. Engaging the half-nut on any numbered line ensures the tool enters the same thread groove every time, preventing the tool from cutting into the crests of the threads already formed.