Student Reference: Cut Parameter Table¶

Material: Low-Carbon Steel (ASTM A36, Cold-Rolled)¶

Cutting Parameters by Thickness¶

Thickness	Amperage	Voltage (V)	Gas Pressure (PSI)	Cut Speed (in/min)	Kerf Width	Expected Dross	Notes
1/16" (1.6mm)	40 A	120 V	45	200–250	0.15"	Light	Fast cut; watch for bevel
1/8" (3.2mm)	65 A	145 V	55	150–180	0.18"	Light–Medium	Standard; good quality
3/16" (4.8mm)	100 A	165 V	60	100–130	0.20"	Medium	Increase pressure if dross appears
1/4" (6.4mm)	130 A	180 V	65	80–100	0.22"	Medium	Standard industrial thickness
3/8" (9.5mm)	160 A	195 V	70	50–70	0.25"	Medium–Heavy	Multiple passes may be faster
1/2" (12.7mm)	200 A	210 V	75	35–50	0.28"	Heavy	Multiple passes recommended

Material Properties (Reference)¶

Melting Point: 1,425°C
Electrical Conductivity: ~10% IACS (International Annealed Copper Standard)
Thermal Conductivity: ~50 W/mK
Oxidation Tendency: Low (forms simple iron oxide at surface)

Cutting Notes¶

Low-carbon steel is the easiest material to plasma cut
Dross accumulation increases with thickness and decreased cut speed
Bevel (angled edge) is typically <3° for well-maintained systems
Cut quality remains consistent from thin to thick materials

Material: Stainless Steel (AISI 304/316)¶

Cutting Parameters by Thickness¶

Thickness	Amperage	Voltage (V)	Gas Pressure (PSI)	Cut Speed (in/min)	Kerf Width	Expected Dross	Notes
1/16" (1.6mm)	40 A	125 V	50	180–220	0.16"	Light	Use nitrogen or argon/H₂
1/8" (3.2mm)	65 A	150 V	60	130–160	0.19"	Light–Medium	Slightly slower than steel
3/16" (4.8mm)	100 A	170 V	65	90–120	0.21"	Medium	Stainless cuts cleanly if parameters right
1/4" (6.4mm)	130 A	185 V	70	70–90	0.23"	Medium	Watch for oxide layer on edge
3/8" (9.5mm)	160 A	200 V	75	45–65	0.26"	Medium–Heavy	Nitrogen gas produces best edge
1/2" (12.7mm)	200 A	215 V	80	30–45	0.29"	Heavy	Multiple passes or slower single pass

Material Properties (Reference)¶

Melting Point: 1,400–1,450°C
Electrical Conductivity: ~2% IACS (lower than carbon steel)
Thermal Conductivity: ~16 W/mK (much lower than carbon steel)
Oxidation Tendency: High (forms chromium oxide passive layer; easily re-oxidizes at edge)

Cutting Notes¶

Stainless steel requires higher voltage than carbon steel for the same amperage (lower conductivity)
Chromium oxide layer on cut edge is undesirable; use nitrogen gas to minimize oxidation
Slower cut speeds produce cleaner edges with less oxide buildup
Dross is heavier and more adherent than carbon steel; post-finishing may be required

Material: Aluminum (5xxx/6xxx Series)¶

Cutting Parameters by Thickness¶

Thickness	Amperage	Voltage (V)	Gas Pressure (PSI)	Cut Speed (in/min)	Kerf Width	Expected Dross	Notes
1/16" (1.6mm)	30 A	110 V	40	300+	0.14"	None	Excellent surface finish
1/8" (3.2mm)	50 A	135 V	50	200–250	0.16"	Light	Fast cutting; low amperage
3/16" (4.8mm)	80 A	160 V	60	120–160	0.19"	Light	Good quality; use argon gas
1/4" (6.4mm)	100 A	175 V	65	80–120	0.21"	Light–Medium	Excellent edge quality
3/8" (9.5mm)	130 A	190 V	70	50–80	0.24"	Medium	Thermal conductivity is high; watch voltage drop
1/2" (12.7mm)	160 A	205 V	75	35–60	0.27"	Medium	Very high thermal conductivity; challenging

Material Properties (Reference)¶

Melting Point: 650–660°C (lowest of common metals)
Electrical Conductivity: ~35–40% IACS (excellent; better than steel)
Thermal Conductivity: ~150–240 W/mK (very high; draws heat away from cut)
Oxidation Tendency: Very high (aluminum oxide, Al₂O₃, is extremely hard and acts as insulator)

Cutting Notes¶

Aluminum's high thermal conductivity and low melting point create a narrow "cutting window": too low amperage and the metal won't melt; too high and you lose dimensional control
High electrical conductivity means plasma arc couples well to aluminum; cutting is efficient
Use argon gas for best quality (argon produces more stable arc on aluminum than nitrogen or air)
Oxide layer on surface acts as insulator; clean surface with a wire brush before cutting
Excellent cut quality and virtually no dross if parameters are optimized
Aluminum is best plasma cutting material if you have the right system parameters

How to Use This Table¶

Step 1: Identify Material & Thickness¶

Know what you're cutting (carbon steel vs. stainless vs. aluminum)
Measure the thickness with a caliper or thickness gauge
Find the nearest row in the appropriate material table

Step 2: Set Amperage¶

The amperage column is the primary parameter; set your power supply to this value
If your material is between two rows (e.g., 3/16" stainless), interpolate: use the amperage for the next thicker material

Step 3: Verify Voltage¶

Voltage should approximately match the table value
If your power supply does not allow voltage adjustment, the supply should regulate automatically; verify the voltage with a multimeter

Step 4: Set Gas Pressure¶

Check the gas regulator; the needle should point to the PSI value in the table
Gas pressure is critical; incorrect pressure causes dross and arc instability
Higher pressure = tighter constriction; lower pressure = wider arc and poor stability

Step 5: Perform Test Cut¶

Make a test cut on scrap material of the same type and thickness
Evaluate cut quality (see next section)

Step 6: Adjust if Needed¶

If dross is excessive: increase amperage or decrease cut speed
If bevel is excessive (>5°): increase gas pressure or decrease amperage slightly
If kerf is wider than expected: reduce gas pressure or check for worn nozzle
If hang fire occurs: increase gas pressure or verify workpiece connection

Cut Quality Acceptance Criteria¶

Excellent Cut¶

Dross: None or very light (easily brushed off)
Bevel: <2° (nearly perpendicular cut edge)
Kerf Width: Within ±0.01" of expected value
Surface Finish: Smooth, parallel lines visible (laminar flow)
Edge Condition: Sharp, ready for welding or assembly without cleanup

Acceptable Cut¶

Dross: Light to medium (requires light grinding, but acceptable for secondary parts)
Bevel: 2–5° (noticeable angle, but acceptable for most applications)
Kerf Width: Within ±0.03" of expected value
Surface Finish: Some roughness; minor irregularities
Edge Condition: Functional; may require cleanup before welding

Unacceptable Cut¶

Dross: Heavy, adherent dross (requires significant grinding)
Bevel: >5° (unacceptable for precision work)
Kerf Width: >±0.05" deviation (indicates worn nozzle or pressure issue)
Surface Finish: Rough, irregular; signs of arc instability
Edge Condition: Ragged; requires substantial post-finishing

Troubleshooting Quick Reference¶

Symptom	Cause	Solution
Heavy dross on cut edge	Slow cut speed, low amperage, poor gas pressure	Increase amperage, increase cut speed, check gas pressure
Beveled cut edge (angled)	High gas pressure, worn nozzle, or low amperage	Reduce gas pressure, replace nozzle, increase amperage slightly
Cut stops mid-way (hang fire)	Gas pressure drop, ground clamp loosened, worn electrode	Verify gas supply, tighten ground clamp, replace electrode if worn
Kerf wider than expected	Worn nozzle, excessive gas pressure	Replace nozzle, reduce gas pressure
Poor arc initiation	Damaged electrode, low gas pressure, contaminated workpiece	Replace electrode, increase gas pressure, clean workpiece surface
Uneven cut quality along the line	Uneven torch speed, inconsistent standoff distance	Practice smooth hand speed, use a straight edge or cutting guide

Notes & Safety¶

Always consult OEM manual: This table is a general reference. Your specific system may have different parameters. Always refer to the OEM manual for your equipment.
Test on scrap: Before cutting expensive material, test on scrap to verify parameters.
PPE required: Even when you know the parameters, always wear full PPE (arc-rated jacket, gloves, glasses, hearing protection).
Ventilation: All materials produce fumes during plasma cutting. Ensure ventilation is running.
Gas type: The gas specified in the OEM manual must be used. Using the wrong gas produces poor quality and safety hazards.

Table Version: 1.0 Created: 2026-03-15 Note: This table is a teaching reference. Always consult OEM documentation for your specific system before making cuts in production.