Gas Cutting Nozzles FAQs
Straight answers to the questions people ask most when choosing and using gas cutting nozzles.
Will a nozzle fit my cutting torch?
Nozzles are made to fit particular torches. The seat, the thread or nut, and the way the gases are fed all vary, so the nozzle must match the torch type and the maker's range. Torches also differ in how they handle the gases: injector (low-pressure) torches draw the fuel gas in using the oxygen flow, while positive-pressure torches are fed both gases at working pressure, and nozzles for one are not necessarily right for the other. Nozzle-mix designs combine the gases in the nozzle itself.
Check the torch maker's list of nozzles for your model, or the markings on your existing nozzle, before you buy. If you are unsure, our team can help you identify the right one.
How do I clean a cutting nozzle?
Switch off the gases and let the nozzle cool, then clear the preheat holes and the central cutting oxygen bore with the correct size of tip cleaner. Push the cleaner straight in and out with a gentle action, use the cleaner sized for that hole, and do not force it. Never use drills, nails or wire, because they ruin the hole.
Finish by cleaning the outside and the sealing seat with a soft brush and removing any loose dirt. Ports blocked with slag cause a distorted flame, poor cuts and popping, so clean the nozzle whenever the flame looks uneven.
When should I replace a cutting nozzle?
Replace the nozzle when cleaning no longer restores a good flame or a clean cut. Signs include holes that have become enlarged or bell-mouthed, a bent or damaged tip, a cracked or burned end, a damaged sealing seat that leaks, or a nozzle that keeps popping even after cleaning and checking the gas settings.
Cutting nozzles are consumable and wear faster if they overheat, are dropped, or are touched against the work. A damaged nozzle gives poor cuts and can be unsafe if it leaks at the seat, so do not keep using one in poor condition.
Why is my gas cut rough, or why is slag sticking to the underside?
Common causes are the wrong nozzle size for the plate, a worn or dirty nozzle, the wrong gas pressures, a travel speed that is too fast or too slow, and holding the nozzle too close to or too far from the plate. Rust, scale and paint on the plate can also upset the cut.
Clean the nozzle first, then check the pressures against the maker's chart and adjust your speed. Heavy slag on the underside often means you are moving too slowly or have too much heat, while sparks flying up from the top instead of through the plate usually mean the cut is not going right through, because you are moving too fast or using too little oxygen.