Description
PT31 / LG40 Plasma Cutter Consumables NZ – Tips, Electrodes & Cups
If you run a small home plasma cutter in NZ, there’s a bloody good chance it uses a PT31 or LG40 torch.
Same torch family.
Same push-in consumables.
Different name depending who sold it to you.
These torches are everywhere on CUT40-style machines from places like Toolshed, Mitre 10, Trade Me and similar.
If you’re not sure what fits your torch, send me a photo and I’ll tell you.
What Is a PT31 / LG40 Plasma Torch?
PT31 and LG40 are just two names for the same style of torch.
They use push-in consumables.
Nothing screws in.
No threads.
If you can pull the tip out by hand and it pops straight out, you’re in PT31 / LG40 territory.
These are scratch-start style torches and very common on entry-level machines.
How To Tell If You Have PT31 / LG40
Quick checks:
Tip pulls out by hand
Electrode pulls out by hand
Ceramic cup screws onto torch head
No big threaded consumables
If that sounds like your torch, you’re in the right place.
What Parts PT31 / LG40 Uses
PT31 / LG40 torches run:
Cutting tips
Electrodes
Swirl rings
Ceramic cups
That’s the normal wear stuff.
Torch heads, trigger switches and complete torches can also be replaced when needed.
Standard vs Extended PT31 / LG40 Consumables
PT31 / LG40 comes in two lengths:
Standard (short)
Your everyday size.
Extended (long)
Same fit, just longer.
Why extended exists:
Easier to reach into corners
Better visibility
Handy on awkward shapes
Important bit:
Standard tip → standard electrode
Extended tip → extended electrode
Don’t mix them.
Both sizes fit the same torch body.
Nickel Plated Versions
There are also nickel plated versions.
In my experience they seem a bit harder and hold up slightly better.
Not miracles.
Just a small improvement from what I’ve seen over the years.
PT31 / LG40 Electrodes Are Double Ended
Most people don’t realise this.
When one end pits out:
Pull it out.
Flip it over.
Put it back in.
You’ve got a fresh end.
If you flip the electrode, it’s usually worth fitting a fresh cutting tip at the same time.
Tips are basically single-use.
Electrodes give you two lives.
Occasionally A Tip Might Not Seat Perfectly
Haven’t seen it for years, but early days it wasn’t uncommon.
Sometimes tolerances are slightly off.
If you ever get one that doesn’t sit quite right, a small copper washer over the electrode will usually sort it.
Simple fix.
How To Check If It’s The Switch Or The Machine
Where the 2-pin trigger plug goes into your machine:
Unplug it
Look at the two small pins
Turn the machine on
Briefly touch the two pins together with a wide flat screwdriver
If the torch fires, your switch is buggered.
If nothing happens, the problem is somewhere else.
Important: PT31 / LG40 machines use low-voltage trigger circuits.
If you’re not sure, don’t guess.
You can swap the internal switch for a simple clip-on trigger and zip-tie it in place to get more life out of the torch.
It’s only two low-voltage wires.
Easy job.
Common PT31 / LG40 Problems
Tips burning out fast
Dirty steel, low air pressure, dragging the torch, or worn consumables.
Electrode sticking
Usually worn electrode or tip.
Won’t start on rusty steel
Scratch-start doesn’t like rust. Clean a small spot or fit fresh consumables.
Weak or splattery cut
Consumables worn or wrong size.
Fresh consumables fix a lot of cutting issues.
Need Help Identifying Your Consumables?
Send me a photo of:
Your torch head
Your old consumables
I’ll tell you exactly what you need.
Better to ask than guess.