Material Diameter

When you set Thread Type to External, this setting changes to Major Diameter.

For Internal threads this is the diameter of the hole before the thread operation. For External threads this is the diameter of the stock before the thread operation.

The Major Diameter and the Material Diameter determine the amount of material to remove. The operation divides the difference between Major Diameter and the Material Diameter by two.

Example

Material Diameter = 12mm
Major Diamter = 16mm
Stock to Leave = 0
No. of Rough Passes = 1

In this example, (16-12)/2 = 2. Therefore, the one cutting pass removes 2mm. If you set No. of Rough Passes to 2, each pass removes 1mm.