GEORGE'S PLASMA CUTTER SHOP
Here is some good info:
I get these emails and phone calls every day about when to change consumables and how long they should last.
You should check your consumables before you start cutting and make sure they are good.
The electrode is the most important consumable as if its bad it can lead to torch damage faster then any other consumable.
The part of the electrode that makes the arc it called Hafnium, it is in the center of the electrode and will get 3200+ degrees when cutting. As it wears little parts fall out and you get a divot/hole in the end of the electrode. The Hafnium is only about 1/8" deep so you have to keep this in mind before making long cuts or cutting out something on a CNC table.
The time to change the electrode is when the divot/pit/hole in the end of the electrode get to be 1/16" deep or so.
There are a few other reasons to change the electrode also, even if it does not look bad. It is not firing dead center, this will cause poor cutting and excess tip/nozzle wear. Also a bad electrode will cause miss fires or pilot arc problems.
NOTE: YOU CAN NOT SAVE THE ELECTRODE BY SANDING, GRINDING, FILING OR WIRE WHEELING IT!!! SO GET THIS OUT OF YOUR HEAD!!!
This picture shows the Hafnium in the electrode and what happens to the electrode when it is all used up. I used a S45 electrode as a sample, but this will apply to almost all electrodes for all plasma cutters no matter what name you put on them.