[ben_w]

> A 5W laser can cut steel

I've experimented with using a 60 W (I think*) laser on a small steel bracket, and even with the beam holding on a single point for a minute, it made a barely visible dot that you couldn't feel by running your finger over.

* It was nearly a decade ago, but I looked up the relevant hacker space and unless they changed the model, it was 60 watts.

The bracket was around 1cm by 5cm, and around 1mm thick.

[dangrossman]

A 60W CO2 laser won't touch steel (or even paper thin aluminum foil), while a 10W diode can cut through it. The type/wavelength of laser matters greatly.

[lightedman]

60w back then would be a CO2 LASER - that's 10600nm and that basically bounces off any non-oxidized metal.

The fiber marking LASERs at work are 1064nm, and at a mere 20w output, will absolutely eat away at steel with no problems.

Edit: I should note there are CO2 metal cutting LASERs, but they are at very, very high output powers to overcome that reflectivity barrier. You need 500w 10600nm to cut through what a 30w 1064nm could cut. My 80w CO2 barely cuts through heavy-duty aluminum foil, and in many spots it isn't a full cut. A 20w marking LASER at 1064 would obliterate the foil.

[ChrisMarshallNY]

Fair ‘nuff.

I know that a friend had a 3-5W laser (don’t remember -it was a CO2 laser) he used for wood burning, and it was fast.

It may also be what they measure.