Thread Cutting Part 2: Cutting an external thread

Stage 1: Cutting a Chamfer a) Use the metal lathe to cut a small chamfer on the end of the bar to be threaded this will make it easier to start the thread

Stage 2: Choosing the correct Die a) Choose the correct Die. If you want to cut a thread on a piece of 8mm diameter bar choose the M8 Die. Die Die stock holder

Stage 3: Fitting the Die a) Fit the Die into the Die Stock Holder and tighten up all 5 screws Die Die stock holder

Stage 4: Setting Up a) Apply a little thread cutting paste to the end of the bar b) Fix the bar securely in the vice (you may have to remove the vice guards to get a better grip)

Stage5: Cutting the thread Cut Thread Break Swarf a) Holding the Die Stock Holder as level as possible start turning the die in a clock wise direction. b) Once the die starts cutting, solid resistance to the cutting action will be felt. At this point the die should be turned back about ½ a turn to break off the swarf. This process should be repeated until the desired length of bar is threaded

Stage5: Testing the thread Clean the cutting paste off the bar then use a nut to test the thread

This is one of the most common types of die. The split in the side allows the die to be adjusted to cut a slightly larger or smaller thread. To cut a slightly larger thread you first slacken the two outside adjustment screws then tighten the centre screw. This will open up the die. Conversely to cut a smaller thread you must loosen the centre screw then tighten the two outside screws. Circular Split Die Adjustment Screws Split

The End