Plasma Consumables Guide: Electrodes, Nozzles and When to Change Them
Posted by Adam Malec on 5th Nov 2026
Plasma cut quality depends on the two smallest parts in the torch: the electrode and the nozzle. As they wear, the arc wanders, the kerf widens and edges bevel, often long before anything looks broken. This guide covers how to match consumables to your torch, how to tell when they're worn, and what we stock for Thermacut EX-TRAFIRE and Tecmo-pattern torches.
What each part does
- Electrode: carries the arc. Its hafnium insert erodes a little with every arc start, so it's the part that wears fastest. A pitted electrode gives a wandering arc and bevelled edges, and quickly damages a new nozzle.
- Nozzle: its orifice shapes and focuses the arc. Once it erodes or gouges, the kerf widens and the cut edge loses its squareness.
- Shield / swirl ring / holder: controls gas flow and protects the nozzle. Some fine-cut nozzles need a matching shield.
Change the electrode and nozzle as a pair. It keeps cut quality consistent and stops a worn electrode wrecking a fresh nozzle.
Step 1: identify your torch
Consumables are torch-specific, not amp-specific. Match the part number to the torch, and compare the listing photo with the part you're replacing before ordering.
- Thermacut EX-TRAFIRE SD (40SD, 45SD, 55SD, 75SD, 100SD): SD electrode T-11883 (pack of 5 with spring holder, current design only) and SD nozzles. The nozzles also suit equivalent Hypertherm models.
- Thermacut EX-TRAFIRE HD 45 (45TT torch): electrode EX-2-401-201 and nozzle EX-2-409-201.
- Thermacut EX-TRAFIRE HD 105TTM torch: electrode EX-5-401-051 and 45A nozzle EX-5-410-051.
- Tecmo-pattern PT60 / IPT60 torches (SWS Speedcut 50, UNIMIG Viper Cut 30 / 41PA / 43P / 45P, WIA Cutmatic 45, Lincoln Invertec PC210, Bossweld): PT60 electrodes and PT60 nozzles (0.9mm and 1.1mm).
- Tecmo-pattern 80A torches (UNIMIG Viper 45 and 80, SC80 / SCM80R, PT80 / IPTM80 machine torch): SC80 / PT80 electrodes.
SD and HD consumables are not interchangeable, and the current SD electrode design doesn't fit the previous one.
Step 2: match the nozzle to your current (SD series)
| Nozzle | Rating | Use |
|---|---|---|
| T-11845 Fine Cut | 45A | Up to 4mm, machine torch; needs the T-12013 shield |
| T-11378 | 45A | Over 5mm; 40SD and 45SD |
| T-11377 | 65A | 55SD |
| T-11405 | 85A | 75SD |
| T-11840 | 105A | 100SD |
Don't run a nozzle above its amp rating, because it erodes the orifice fast. When you cut thinner plate on a big system, drop the current and fit a lower-rated nozzle.
Signs your consumables are worn
- The arc wanders or is hard to start.
- The kerf is wider than usual, or edges are bevelled on one side.
- There's more dross on the bottom edge with the same settings.
- The nozzle orifice looks oval or gouged, or the electrode insert has a visible pit.
- On a CNC table, torch height control becomes unstable, because arc voltage rises as the parts wear.
Adam's Tip
Keep a spare electrode and nozzle set beside the table, and change both when cut quality drops, rather than waiting for a failure in the middle of a sheet. Clean, dry air is the other half of consumable life, so drain the compressor and filter regularly.
Frequently asked questions
How often should I change plasma electrodes and nozzles?
Change them when cut quality drops: a wandering arc, a wider kerf, bevelled edges or more dross. Replace the electrode and nozzle together. Pierces and arc starts wear them faster than long cuts do.
Are Thermacut SD and HD consumables interchangeable?
No. SD and HD torches use different electrodes and nozzles. Match the part number to your torch model.
Which nozzle should I use for thin sheet?
On Thermacut EX-TRAFIRE SD systems, the T-11845 Fine Cut 45A nozzle is recommended for material up to 4mm with a machine torch. It needs the T-12013 shield.
Do you stock consumables for UNIMIG and other Australian plasma cutters?
Yes. We stock PT60 / IPT60 electrodes and nozzles for Tecmo-pattern torches on SWS, UNIMIG, WIA, Lincoln and Bossweld machines, and SC80 / PT80 electrodes for UNIMIG 80A torches.