Laser cutting sheet steel fittings?

[drigotti]

Folks,
What are the dangers (if any) of having aircraft 4130 fittings laser cut out? Do the edges become heat treated? How deep? Anyone with experience on this have something to add?

Thank You!

Dave Rigotti

[Todd copeland]

I don't see any danger, it can't be any worse than your saber saw on it. You certainly get a better cut, I would still debur the entire edge just as with any metal edge.

[Bob H]

I did some laser cutting many years ago and found back then that there was a heat affected zone (HAZ) about .020" deep at cut surface. Because the edge cooled quickly, it formed untempered martensite that is brittle and prone to cracking. So I'd cut parts slightly oversized and machine off that HAZ just to be sure. Perhaps the laser cutting technology has improved over the years to stop any HAZ and someone in that business can answer that. To be conservative now, remove that edge.

[drigotti]

Thanks Bob! I'll stick with hand cutting them on a bandsaw. This way I KNOW for sure I haven't messed with the metallurgy.

Dave Rigotti

[Plncrzy]

Hi Dave, On my project I had all my steel parts Water Jet cut, they all came out beautifully and welded just great.

[Bob H]

Just a point of interest- The original water jets did not use any abrasive and were limited to cutting softer materials. Then garnet abrasive was added by entraining it in the water stream and that allowed water jet to really be effective in cutting metals. So the cutting is actually done by the high velocity abrasive which is accelerated by the water. And because the process is done relatively cool, there is no HAZ to contend with.