Technical reference

304 vs 316 Stainless Steel Laser Cutting Parameters

Updated 2026-10-12 · 4 min read

304 and 316 are both austenitic stainless steels and look identical on the shop floor. They cut differently enough to notice, though, and cutting 316 with 304 parameters is one of the most common causes of unexplained dross. Here is what actually differs and how to set up for each.

Quick answer: 316 cuts 5 to 15% slower than 304 at the same thickness and power, because molybdenum makes the melt more viscous and slightly harder to clear from the kerf. Start with the same nitrogen parameters, then reduce speed until the bottom edge is dross-free and raise pressure if needed. Do not assume 316 will cut on 304 settings.

What actually differs between them

	304	316 / 316L
Chromium	18–20%	16–18%
Nickel	8–10.5%	10–14%
Molybdenum	—	2–3%
Carbon (L grade)	0.08% max	0.03% max
Corrosion resistance	Good in most environments	Better against chlorides and pitting
Magnetic behaviour	Mostly non-magnetic	Mostly non-magnetic
Typical use	Food equipment, kitchenware, general fabrication	Marine, chemical, medical, coastal architecture
Laser cutting behaviour	Faster, brighter edge	Slower, more prone to dross

The molybdenum is the cutting-relevant difference. It is added for corrosion resistance — it is what stops chloride pitting in coastal and chemical environments — but it also raises the melting range slightly and increases the viscosity of the melt.

Why 316L is slower to cut

Three effects combine:

Higher melt viscosity. Thicker molten material is harder for the nitrogen jet to expel from the kerf. Material that is not expelled resolidifies as dross on the bottom edge.
Slightly higher melting range. Molybdenum raises the temperature needed to establish and sustain the cut, so the same power delivers less penetration.
Low carbon in the L grade. 316L's carbon content is capped at 0.03% to prevent sensitisation during welding. That is a welding benefit, but it also slightly changes how the melt behaves at the cut edge.

In practice the aggregate effect is a 5–15% speed reduction. That sounds small, but on a machine running stainless all day it is a real throughput difference — and it is the reason a job priced on 304 rates can lose money if the customer supplies 316.

Starting parameters for 304 stainless

Nitrogen assist, focus near the surface. These are starting points — confirm on your own machine.

Thickness	Power	Speed	Focus	N₂ pressure
1 mm	1–1.5 kW	6–8 m/min	−0.3 mm	8–10 bar
2 mm	2 kW	3.0–4.0 m/min	−0.8 mm	10–12 bar
3 mm	3 kW	2.2–3.0 m/min	−1.2 mm	12–14 bar
5 mm	3–4 kW	1.5–2.0 m/min	−2.0 mm	14–16 bar
8 mm	6 kW	1.6–2.2 m/min	−3.0 mm	16–18 bar

Starting parameters for 316 / 316L

Same structure, lower speed, slightly higher pressure.

Thickness	Power	Speed	Focus	N₂ pressure
1 mm	1.5 kW	5–7 m/min	−0.3 mm	9–11 bar
2 mm	2 kW	2.5–3.5 m/min	−0.8 mm	11–13 bar
3 mm	3 kW	1.9–2.6 m/min	−1.2 mm	13–15 bar
5 mm	4 kW	1.3–1.8 m/min	−2.0 mm	15–17 bar
8 mm	6 kW	1.4–2.0 m/min	−3.0 mm	17–19 bar

The gap widens as thickness increases, because the viscous melt has further to travel out of the kerf.

Reading the cut edge

The edge colour tells you what to change, and it is worth learning to read it:

Edge appearance	What it means	What to change
Bright silver, uniform	Correct parameters	Nothing
Pale straw / light gold	Slightly too much heat	Increase speed 5%
Blue / purple	Too much heat, oxidation	Increase speed; check nitrogen purity
Dark grey, rough	Speed too high, or gas pressure low	Reduce speed; raise N₂ pressure
Dross on the bottom edge	Melt not expelled	Reduce speed 5–10%; raise pressure
Heavy dross, hard to remove	Focus too low, or nozzle worn	Raise focus 0.5 mm; replace nozzle
Wider kerf than expected	Focus too high	Lower focus 0.5 mm

A light straw colour is acceptable for most work. Blue or purple on stainless usually means the nitrogen purity has dropped or the pressure is insufficient, not that the speed is wrong.

Cutting above 4 mm

Once you pass about 4 mm, three things change at once and the parameters stop transferring from thin sheet:

Nitrogen pressure must rise. Below about 12 bar the jet cannot clear the deeper kerf, and dross becomes unavoidable regardless of speed.
Focus goes further negative. The beam needs to be focused below the surface to maintain energy density at the bottom of the cut.
Piercing needs managing. A single-stage pierce on 6 mm+ stainless spatters badly and can damage the nozzle. Use a two-stage pierce: a low-power stage to establish the pierce, then full power to cut.

On 316 above 4 mm, expect to spend noticeably longer on parameter setting than on 304, and expect the usable speed window to be narrower.

Cutting cost comparison

The speed difference translates into a real cost difference per part:

Machine time. 5–15% more time per metre on 316, at the same hourly rate.
Nitrogen consumption. 316 needs slightly higher pressure, so gas cost per part rises a little.
Consumables. More dross means more edge cleaning and slightly faster nozzle wear.
Scrap risk. The narrower parameter window on 316 means more risk of a rejected first part during setup.

If you quote 316 work at 304 rates, the margin disappears on the machine time alone. Quote it separately.

Frequently asked questions

Does 316 stainless cut slower than 304?

Yes, but the difference is modest - typically 5 to 15% lower cutting speed at the same thickness and power. The molybdenum in 316 raises the melt temperature slightly and makes the melt more viscous, so it clears the kerf less easily.

Why does 316L produce more dross than 304?

The molybdenum content makes the molten material thicker, and the low carbon grade (L) has a slightly different solidification behaviour. The practical fix is to reduce speed by 5-10% and increase nitrogen pressure slightly.

Can I use the same parameters for 304 and 316?

You can start from the same entry, but expect to slow down 5-15% and possibly raise nitrogen pressure for 316. Cutting 316 with 304 parameters usually gives dross on the bottom edge.

Which is better for laser cutting, 304 or 316?

304 cuts faster and gives a brighter edge. 316 is chosen for corrosion resistance in chloride environments, not because it cuts better. If the part does not need 316's corrosion performance, specify 304 and cut faster.

Machines mentioned in this article

Fiber Laser Cutting Machine — PL-1390 with Raycus source and Raytools head
PL-M30S Marking Machine — Set up for stainless steel marking
Cutting Parameters Chart — Starting points for all common materials

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