0 items in your basket
Total £ 0.00 EX VAT
MIG Gloves
TIG Gloves
Baseball Caps
Armguards
TIG Heat Blockers
Shop 55,000 Products
SERVICEDEPT.
RAPID BLOG
FEEDBACK
HIRE
Straight answers to the questions people ask most when choosing and using gas cutting nozzles.
Cutting nozzles are sized for the thickness of steel you cut. The nozzle size sets how much oxygen and fuel gas flows, so a bigger nozzle suits thicker plate and a smaller one suits thin sheet. Each maker publishes a chart relating nozzle size to thickness and giving the oxygen and fuel gas pressures to use, and you should work from the chart for your own nozzle type.A nozzle that is too large wastes gas and gives a wide, rough cut, and one that is too small cannot cut cleanly through the plate. Choose for the thickness you cut most, and use a different nozzle for much thicker or thinner jobs.
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.
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.
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.