Examine the electrode for emitter wear

Emitter wear can indicate when to replace the electrode. Increasing the number of starts and the arc-on time can cause the emitter to wear more quickly. Emitter wear can cause the cut quality to decrease. Your cut-quality requirements will indicate when to replace the electrode.

Figure 1. Example of a new electrode
This image shows an example new electrode and approximate locations of the electrode pit, hafnium emitter, and electrode face.
1 Electrode pit
2 Hafnium emitter
3 Electrode face
Note:

If an electrode needs replacement because of emitter wear, always replace the nozzle at the same time as the electrode. Use the electrode torque tool (429013) to correctly tighten the electrode.

  1. Examine the electrode pit diameter for these conditions:
    1. If the diameter extends beyond the hafnium, replace the electrode and nozzle.
      This image shows an example used electrode with pitting that extends beyond hafnium.
    2. If you see a non-symmetrical, rough-edged pit and rough-surfaced electrode face, replace the electrode and nozzle.This image shows a used electrode with non-symmetrical pitting.
  2. Use an electrode pit-depth gauge to measure the pit depth on the electrode.

    A pit-depth gauge is available from Hypertherm®.

    This image shows how to measure pit depth.
    1 Electrode pit
    2 Pit-depth gauge
    Note:

    The electrode shown is not to scale.

  3. Replace the electrode and nozzle if your pit-depth measurement is outside of these guidelines:
    Electrode amperage Replacement pit depth 1 Description
    < 130 A ≥ 1 mm (0.04 in) In general, for electrodes less than 130 A, replace the electrode when the pit depth is 1 mm (0.04 in) or more.
    ≥ 130 A and < 220 A ≥ 1.25 mm (0.05 in) In general, for electrodes more than or equal to 130 A and less than 220 A, replace the electrode when the pit depth is 1.25 mm (0.05 in) or more.
    ≥ 220 A ≥ 1.5 mm (0.06 in) In general, for electrodes more than or equal to 220 A, replace the electrode when the pit depth is 1.5 mm (0.06 in) or more.
    1 Based on your cut-quality requirements, it can be necessary to replace your electrode at a pit depth that is shallower or deeper than these guidelines.