Oxy-Acetylene Cutting Settings: PSI & Tip Size Chart
Oxy-acetylene cutting pressure depends on tip size and metal thickness, not one fixed number: a Victor 000 tip runs 15-20 PSI oxygen on 1/8″ sheet, a #3 tip needs 40-55 PSI on 2″ plate, and acetylene never goes above OSHA’s 15 PSI limit. Guessing wastes gas or ruins the kerf. This guide covers the Victor/Harris tip chart, the exact PSI range per thickness, and the lighting sequence that keeps every setting safe.
Oxy-Acetylene Cutting Tip Size Chart by Metal Thickness
Tip size, not a flat oxygen number, is what actually changes with metal thickness. The chart below uses the Victor 101-series numbering (the most common one-piece cutting tip in small and mid-size shops); Harris 6290-series tips cover the same thickness ranges under a different number. Pick the tip rated for your material, then set the regulator to the pressure listed for that tip — not a generic number pulled from a forum post.
| Victor Tip | Thickness | Oxygen PSI | Acetylene PSI |
|---|---|---|---|
| 000-1-101 | Up to 1/8" | 15-20 | 3-5 |
| 00-1-101 | 1/8"-1/4" | 20-25 | 3-5 |
| 0-1-101 | 1/4"-1/2" | 25-30 | 5-7 |
| 1-1-101 | 1/2"-1" | 30-40 | 5-7 |
| 2-1-101 | 1"-2" | 35-50 | 5-8 |
| 3-1-101 | 2"-3" | 40-55 | 6-8 |
As a quick rule of thumb, the tip number roughly matches the maximum thickness in fractions of an inch — a #1 tip tops out near 1", a #2 near 2". Harris tips use a simpler single-number system (6290-0, 6290-1, 6290-2) that lines up with the same thickness bands, but the two brands aren’t interchangeable; check your specific manufacturer’s tip chart before cutting.
Which Tip Handles Half-Inch Steel?
A Victor 1-1-101 or Harris 6290-1 tip handles 1/2" steel. Set oxygen to 30-35 PSI and acetylene to 5-7 PSI; expect a clean kerf around 0.055-0.06" wide and a cut speed of roughly 14-18 inches per minute once the plate is preheated to a dull cherry red.
Best Cutting Torch Tip Cleaner Pick
ALLY Tools 12-Wire Oxy-Acetylene Tip Cleaner Set
Twelve graduated wire sizes for clearing clogged preheat and cutting orifices without enlarging them.
- Best for: clearing clogged preheat and cutting orifices on Victor and Harris style tips
- Why we picked it: 12 wire sizes span the full 000-6290 range in the chart above, one set covers sheet metal through heavy plate
- Main drawback: wires aren’t sold separately, a snapped wire means replacing the whole handle
Compare more cutting torch tip options
 Option 1 WILLBOND Torch Tip Cleaner Kit
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 Option 2 Victor-Style 1-101 Series Cutting Tips
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 Option 3 VASTOOLS Torch Striker Set
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How to Set Oxygen and Acetylene Pressure
Clear the work area and clamp the metal before touching a regulator — a piece that shifts mid-cut is the most common cause of a ruined kerf, not a wrong PSI number. Then work through the sequence below in order.
- Close both torch valves: shut the acetylene and oxygen valves on the torch handle before touching either cylinder.
- Crack the acetylene cylinder valve: open it 1/4 to 1/2 turn only — acetylene cylinders are never opened fully.
- Set the acetylene regulator: dial to the chart pressure for your tip, staying well under the 15 PSI ceiling.
- Fully open the oxygen cylinder valve: unlike acetylene, the oxygen valve opens all the way.
- Set the oxygen regulator: match the chart’s cutting-oxygen PSI for the tip you selected.
- Light the acetylene and add oxygen: ignite with a striker, then slowly introduce oxygen until the preheat cones form.
- Tune to a neutral flame: keep adding oxygen until the flame forms sharp, well-defined blue cones with no feathery edge.
- Test the cutting-oxygen lever: press it briefly — if regulator pressure drops more than 5 PSI, the tip is too small for the job and needs to size up.
What Pressure Should You Set for Oxy-Acetylene Cutting?
Without a manufacturer chart, 40 PSI oxygen and 10 PSI acetylene is the accepted fallback for hand-cutting steel under 1-1/2" thick. For anything thicker, or for a clean edge on thin sheet, use the tip-specific numbers in the chart above rather than one flat setting for every job.
Acetylene Safety Limit: Why You Never Exceed 15 PSI
Acetylene is unstable at pressure. Above roughly 15 PSIG, it can decompose on its own — without any oxygen present — releasing energy fast enough to detonate. That’s why every acetylene regulator has a red line at 15 PSI and why it’s a hard limit, not a suggestion.
“Never exceed 15 pounds per square inch (psi) when using acetylene.”
If you’re new to lighting and adjusting the torch itself — not just dialing in pressure — see our guide to using an oxy-acetylene cutting torch for the full step-by-step operating and shutdown sequence.
Common Cutting Problems and the Setting Behind Them
Most cutting defects trace back to a pressure or tip mismatch rather than operator skill.
- Excessive slag on the cut face: tip too large for the thickness, oxygen pressure too low, or travel speed too slow.
- Cutting oxygen drops when the lever is pressed: the tip can’t flow enough oxygen for the thickness — step up one tip size.
- Wide, rough kerf on thin material: tip too large; drop down a size for a narrower, cleaner cut.
- Preheat flame keeps going out: gas pressure too low, orifices clogged, or a leaking tip seat.
Wearing flame-resistant clothing, gloves, and shade 5 goggles, and keeping the area ventilated, prevents most of the safety incidents that show up alongside these cutting problems — a leaking tip seat or an over-pressured acetylene line is a fire and flashback risk, not just a cut-quality issue.
Maintaining Your Cutting Tips
Clean tips after every session with a graduated tip cleaner sized to each orifice — push straight in and out, never ream or twist, and never use a drill bit, which permanently enlarges the hole and throws off every pressure setting in the chart above. Replace a tip once its orifices look oblong or the tip face is gouged from slag contact; a $5-15 tip is cheaper than the wasted gas and poor cuts a worn one produces.
Frequently Asked Questions For Oxy Acetylene Cutting Settings
What Are The Ideal Cutting Settings For Oxy Acetylene?
Ideal settings depend on tip size and metal thickness, not one number. A 000 tip on 1/8" sheet runs 15-20 PSI oxygen and 3-5 PSI acetylene; a #1 tip on 1/2"-1" steel runs 30-40 PSI oxygen and 5-7 PSI acetylene; a #3 tip on 2"-3" plate runs 40-55 PSI oxygen and 6-8 PSI acetylene. Acetylene should never exceed 15 PSI regardless of tip size.
How Do I Set The Oxygen Pressure For Oxy Acetylene Cutting?
Close both torch valves, fully open the oxygen cylinder valve, then adjust the oxygen regulator to the cutting pressure listed for your tip size in the chart above — 15-20 PSI for the smallest sheet-metal tips up to 50-65 PSI for heavy plate tips. Always confirm against the torch manufacturer’s own chart, since tip-to-pressure ratios vary slightly between brands.
What Acetylene Pressure Should Be Used For Oxy Acetylene Cutting?
Acetylene pressure stays in a narrow 3-8 PSI band across almost every tip size, unlike oxygen, which climbs with thickness. Crack the acetylene cylinder valve only 1/4 to 1/2 turn, and never set the regulator above 15 PSI — OSHA’s hard limit, above which acetylene becomes unstable even without oxygen present.
What Size Cutting Tip Do I Need for 1/2 Inch Steel?
A Victor 1-1-101 or Harris 6290-1 tip is sized for 1/2" steel. Set oxygen to 30-35 PSI and acetylene to 5-7 PSI for a clean kerf around 14-18 inches per minute of travel speed.
Why Do Victor and Harris Tip Numbers Differ?
Victor and Harris use different numbering systems for the same job. A Victor 0-1-101 and a Harris 6290-0 both cover roughly 1/4"-1/2" steel, but the numbers aren’t interchangeable between brands. Always match the tip chart to the torch brand you actually own.
Conclusion
Match the tip to the metal thickness first, then set oxygen and acetylene to that tip’s chart pressure — not a flat number that ignores what you’re actually cutting. Keep acetylene under 15 PSI, keep tips clean, and check the manufacturer’s own chart whenever it’s available. For general torch operation and lighting technique, see our oxy-acetylene torch usage guide, and for a smaller torch suited to detail work, see our guide to the smallest cutting torches.
