Laser Feed Rate Calculator
Estimate cutting feed rate, pierce delay, kerf allowance, cut time, and table settings from material, thickness, wattage, assist gas, and edge quality.
Laser Cutting Results
| Material | Good laser match | Starting speed behavior | Typical gas |
|---|---|---|---|
| Mild steel | Fiber | Medium, oxygen can increase heat | Oxygen or air |
| Stainless steel | Fiber | Slower for oxide-free edges | Nitrogen |
| Aluminum | Fiber | Reflective, needs stable focus | Nitrogen |
| Acrylic | CO2 | Fast with polished edge potential | Air |
| Plywood | CO2 | Fast, resin and glue vary widely | Air |
| Brass or copper | Fiber | Reflective, use conservative trial cuts | Nitrogen |
| Assist gas | Factor used | Best use | Calculator effect |
|---|---|---|---|
| Air | 1.00 | General cutting and organics | Neutral feed estimate |
| Oxygen | 1.18 | Mild steel heat-assisted cutting | Raises steel speed estimate |
| Nitrogen | 0.88 | Clean stainless and aluminum edges | Slows for edge quality |
| Argon | 0.78 | Special non-reactive cuts | Conservative feed estimate |
| None | 0.55 | Marking or very thin trials only | Large speed reduction |
| Cut class | Typical kerf | Nozzle range | Use in calculator |
|---|---|---|---|
| Thin sheet fiber | 0.08 to 0.18 mm | 0.8 to 1.5 mm | Small allowance, quick pierce |
| Medium plate fiber | 0.18 to 0.35 mm | 1.2 to 2.5 mm | Normal allowance and delay |
| Thick plate fiber | 0.35 to 0.70 mm | 2.0 to 4.0 mm | Slow feed, longer pierce |
| CO2 acrylic | 0.15 to 0.35 mm | 1.5 to 3.0 mm | Moderate kerf, cleaner edge |
| Wood sheet | 0.20 to 0.55 mm | 1.5 to 3.0 mm | Extra allowance for char |
| Preset | Material and thickness | Laser and gas | Expected setting range |
|---|---|---|---|
| 3 mm Mild Steel | 3 mm mild steel | 1.5 kW fiber, oxygen | Fast shop baseline |
| 2 mm Stainless | 2 mm stainless | 2 kW fiber, nitrogen | Clean edge baseline |
| 6 mm Acrylic | 6 mm acrylic | 100 W CO2, air | Moderate, single pass |
| 6 mm Plywood | 6 mm plywood | 130 W CO2, air | Resin-dependent trial |
| 10 mm Plate Steel | 10 mm mild steel | 4 kW fiber, oxygen | Slow plate cutting |
The vast majority of problems with laser cutting happen in the first couple seconds of use. It happens the moment you hit start and beam hits the metal. What was supposed to be a nice clean cut turns into melted holes, a corner of the material gets sheared off, or a whole bunch of sparks fly everywhere.
Typically, it’s because someone new has one variable they can’t quite get right, and feed rate isn’t some magic knob. Feed rate are a mix of material properties, time, and energy that you have to balance out. Luckily there’s a calculator for this, but knowing why those values is important helps you avoid screwing up anything you’re trying to cut.
Why Laser Cutting Problems Happen
Laser cutting is analogous to driving. You have an engine (wattage) that gives you power, and you have a speed (feed rate) to move over a surface area. A powerful car will sink if you take it through a swamp. Similarly, heavy truck can’t go fast down a highway without risking engine failure.
There is differences in materials depending on how they reflect or conduct heat. Mild steel, for instance, is very receptive to heat, even more so if oxygen helps it create heat through a chemical reaction. Other materials such as stainless steel and aluminum reject the heat different. For example, aluminum will reflect laser beam. This requires slower speeds and careful focus to bring the energy into the material instead of reflecting it away from the material.
What kind of assist gas is used? The type of gas you use has an effect on the physics of the cut. A lot of folks use air (free). That makes sense if you are cutting thick wood or acrylic, where you don’t care about the edge so much as getting the junk blown away.
For stainless steel, though, a special result requires payment: no oxidation means keeping your edges bright and prepped to be polished or welded. To take account of this in the calculator, I have adjusted the estimated speeds downward based on a nitrogen cut vs it is an oxygen cut. You might think it’s odd that a clean cut is slower then a dirty one, but remember that we’re prioritizing quality rather than speed. If you go too fast with nitro, dross will form on underside of the cut. This defeats the purpose of using expensive gas and makes the cut rough and oxidized.
Another issue is kerf width. Laser beams has a physical width and when they cut, they remove some of the material in their path. This is the kerf. So if you are trying to create a part that is precisely ten millimeters wide and don’t account for the kerf, your part will end up narrower than desired. The tool requests that you enter kerf so it knows how long it will take and how much material should of been wasted.
One misstep people make is thinking the kerf is consistent. It isn’t. Depending on material thickness, nozzle size, and lens focal length, the kerf size change. A 1.5 kW fiber laser cutting three millimeters of steel might have a kerf of 0.15 millimeters. 3 millimeters since the beam spreads out more across that distance.
The time the laser waits before moving to burn a hole is called Pierce Delay. Set it too long and you make a big hole that’s not so great, wasting time. Set it too short and you don’t have a full hole when it tries to start cutting. The calculator figures out how long it should be for your material type and thickness. Thicker stuff need more time to get started cleanly.
That’s also why it can sometimes take longer per part to cut a sheet of multiple small shape as opposed to just one big shape. Pierce time accumulates fast.
Always start out by testing on scrap material. There is no calculator for a misaligned nozzle or a dirty lens. There is also no way to calculate a batch of material with unexpected alloy variations. Start at the estimated feed rate, and make small adjustments from there. Slow down if edge is rough. Speed up a little if the process is taking longer than you like but the edge is clean. You want the fastest speed that still maintains your desired level of quality.
When you determine the right speed for this particular material and machine, run it consistently. Small speed increases don’t matter nearly as much as consistency. These numbers serve as a starting place. When the cut is complete, you know based off what you see.
