Cutting Very Thin Stainless Steel

[Mike Rags]

Hello,
My name is Mike, I have been looking at buying a laser for the last year or so. I was wondering if an 80 watt CO2 laser can cut through very thin stainless steel 0.005in (5mils)? Has anyone tried this? I could also purchase a 120watt or 150watt if they would be able to.

If anyone wants to give it a try and report back, I can mail off a piece of 0.004in SS stock. Thanks for the help.


Mike

[Gary Hair]

I don't know what the minimum wattage would be for cutting metal, but I am know that 80 watts won't do it, I don't think 120 or 150 will either. Someone here will probably have the right answer but not me. I have a customer/vendor that cuts metal and his lasers are 2,000 and 4,000 watts - that should give you some idea.

Gary

[Mike Rags]

Thanks Gary, Yeah I imagine a 2,000 to 4,000watt machine is needed to cut any real thickness of metal, but for 5mils, which is really thin, I think 80 watts has a chance. I am not sure anyone has tried yet? If anyone has a 80watt to 150 watt machine, I would sent them the sample to give it a try.


Mike

[paul mott]

The CO2 wavelength is not optimum for cutting metals and 80Watt will not do it - you need to be in the kW range for success and then oxygen is used as the assist gas. As you can imagine his can be quite dangerous unless adequate safety precautions are in force.
YAG lasers, on the other hand, are ideal for metals and even the 50Watt when used with a 'Q switch' will easily perforate thin stainless.

Paul.

[Michael Hunter]

Kern lasers claim to cut thin stainless, starting with their 150W model. I think that they use oxygen (rather than air) assist for this.

[paul mott]

Kern lasers claim to cut thin stainless, starting with their 150W model. I think that they use oxygen (rather than air) assist for this.

I stand corrected, If Kern say that it can be done with 150 Watts then that is what it takes.

There is some more interesting info on their site including glass cutting.

Paul.

[Dan Hintz]

Thanks Gary, Yeah I imagine a 2,000 to 4,000watt machine is needed to cut any real thickness of metal, but for 5mils, which is really thin, I think 80 watts has a chance
It's not an issue of power, per se, it's an issue of wavelength. Metals are highly reflective to the wavelength of a CO2 cartridge, but not completely, so you have to really pour in a lot of power to get a cut (read, inefficient). I was going to suggest 200W as a minimum for 5mil, but if Kern claims 150W, I would be willing to try it. 80W is just going to tick it off...

[Mike Null]

Kern can do it.

This is from their web site.


The 150 watt laser will cut up to a thickkness of .090" mild steel and .075" stainless steel. The 400 watt laser will cut up to .1875" mild steel, .125" stainless steel and some aluminum alloys up to .050". The 400 watt laser will also cut thinner gauge brass, titanium and nickel. Please feel free to send us your metal material to determine the feed rate and edge quality the KERN Metal Cutter can produce.

[David Fairfield]

The Kern sample packet includes laser cut metal bits and other things. Its a very capable machine. Note the edge quality might be an issue for very fine cutting, there are small "burrs" of melted & solidified material, but machine cutting can leave similar burrs, so no points deducted for that!

Dave

[Richard Rumancik]

Maybe Synrad could give you an opinion. On their site they have this example of stainless cutting:
http://www.synrad.com/search_apps/application_briefs/69-1.htm

This shows a 240 watt laser cutting .024" stainless using oxygen assist at 75 inches/minute.

Here's another cutting .018 stainless tube.
http://www.synrad.com/search_apps/application_briefs/44-1.htm

They are actually cutting quite fast. I would ask if oxygen is mandatory or whether you could take a speed hit and cut with air assist. The oxygen will require buying a regulator and requires oxygen tank rental, plus cost of oxygen itself. Also you might need a better nose cone, as most low cost lasers don't have a proper coaxial nosecone to deliver the oxygen effectively. The Kern probably has a better nose cone but I did not actually look at it.

[Michael Hunter]

Note the edge quality might be an issue for very fine cutting, there are small "burrs" of melted & solidified material, but machine cutting can leave similar burrs, so no points deducted for that!

This seems to be a common problem with laser-cut metal.
I get to see quite a lot of stainless from 0.5 to 3mm thickness and also 2mm aluminium : deliveries frequently have tiny "beads" of metal along the cut lines - particularly inside small holes. The 0.5mm SS also has metal flakes from molten metal that has been blown across the surface and has stuck. Lots of cleaning up!
This is from a multi-kW machine which is said to have cost (with sheet loader and unloader) at the time nearly $3 million.

Just wish I could cut metal on my Epilog!

[Paul Phillips]

Mike,
Yeah, I was drooling over the 400watt Kerns when I was shopping around last year but they were out of my price range. My Universal 120watt tested out at 152watts when it was first set up. While testing different materials to see what it could do I was able to barely get through some .025 mild steel sheet with my air assist turned up to about 60psi but there was a lot of slag and it warped the area pretty bad from all the heat. I'm not sure how much it has "relaxed" on the power after about 10 months of use but I'll be happy to give it a try if you want to send me the sample. PM me if you want contact info. Good luck, Paul.

[Bruce Boone]

I tried .020" titanium and almost got through with my Universal CO2 laser putting out around 130 watts. I imagine it could do .005" stock. I can try it out if you want to send me a sample.

I have looked for years for a laser that could do that yet be at the edge of affordable. I know that there are 20 watt fiber lasers out there for around $40K that will definitely do it. I saw it done at a jewelry show. It could cut around .020" stock. As a matter of fact, stents are made this way. They start as a thin wall tube and everything gets lasered away with about a 20 watt fiber laser. The trick is the wavelength being 1/10th that of a CO2 laser. I was looking to cut through at least 2mm titanium, so kept looking. I finally found a maker of an 80 watt YAG laser that can do it, so I have it on order.

[Dean Fowell]

We Have a 1500 watt laser but you need to cut stainless with nitrogen no burs or cleaning up, I have also cut .312 thick stainless on a 3000 watt, using oxygen does not leave a nice cut

185598

[John Minton]

There seems to be some mis-information out there. Few people cut stainless with Yag almost all is done with co2. As Dean has posted 1500 watt will cut stainless very well with Nitrogen. We have a 1500 watt machine that will cut 3/16 with nitrogen and 3/8 with oxygen. We have been cutting metal since 1992. we have a 1500, 2600 and 4000 watt machine. I have always been told that anything under 400 watts will not give you the outcome you will be happy with. I have a 80 watt machine for cutting non-metals we tried to cut stainless shim stock yes it cut it but not well and not something you would want to run production on. Hope this helps.

John

[Bruce Boone]

The fiber lasers and YAG lasers actually ablate (vaporize) the material, so there is very little slag. They have an extremely fine beam of around .001" whereas the CO2 beam will usually be a lot wider than that.

Here's a picture of what a 20 watt fiber laser can do: http://www.rofin.com/index.php?id=533&L=1 Very crisp detail and accurate cuts and probably around .010" deep in the picture. These types of lasers are relatively new on the scene. It won't be able to cut much deeper than what's shown, so it's not for a job shop, just for very specific purposes.