Threading

The program format for G33 Threading parallel (Constant Pitch) looks like this:

Program format: G33 X..., Z.... F...

X: Diameter of each treading cycle pass
Z: End point of threading
F: Thread Pitch

Program example

Description og steps in Threading Cycle (drawing) above:

1. The tool moves (1) at rapid traverse to the starting point of the thread cutting.
2. The tool moves (2) to the first X diameter position for Threading.
3. The tool moves (3) along the Z axis at the F pitch of the Thread synchronised with the spindle. (F2 for a thread pitch of 2 mm).
4. The tool moves (4) clear of the workpiece at the specified feed rate.
5. The tool moves (1) back to the starting point of the threading cycle at rapid traverse.

For each X position the cycle is repeated.
The number of extra passes at the final X position is dependent on the work piece material. Usually 2 passes are selected (Spring Passes).

At every X diameter the Cycle is executed.
For each new X dimension, the cycle is executed. The number of spring finishing passes at the final X diameter must be selected according to thread pitch, workpiece material, etc.

At each new X position the cycle is executed.
The number of spring finishing passes at the final X position must be selected depending on thread pitch, workpiece material, etc.

Program example with descriptions

Assignment: Threading

Prepare a program for the drawing below where a roughing is made with an external screw steel. Chipping depth must be 5mm in diameter. Then a finishing operation must be carried out with an external copy steel. Make an M30 * 1.5 mm thread using the G33 Cycle.