TIL: How strong stainless steel is (NOTE: Post updated, corrected, and apology enclosed.)

[Steve Crewdog]

*******NOTE*******
Member hgerhardt pointed out that I had assembled the punch wrong. He was right, I was wrong, but I'm leaving the thread up for those who have already seen the thread, and to show that a punch will work on stainless steel. I screwed up.
*****************


Needed a mount for a vertical card compass. Holy cow, look how expensive they are! I've got an extra range hood shroud left over from Honey's new kitchen, it's already bent and thin, perfect for a compass mount.

Last night: burned through a hole saw.
Today: Instrument hole cutter didn't even start to penetrate the metal.


Where's that scrap 050?

 

[rv8ch]

I learned this cutting through the stainless steel firewall. It was an experience!

 

[Mike S]

High pressure and slow rpm seems to work best for me when drilling SS.

But, there are so many different formulas of SS that who knows what a range hood is made of?

 

[hgerhardt]

The punch is assembled backwards, with the cutting edge pointed away from the female side. If that's truly the orientation you used, that's why it only folded the metal instead of cutting.

 

[RV7 To Go]

I have cut numerous holes in SS using bi-metal hole saws. Use a low speed, lots of cutting oil or WD40 to help keep the cutter cool. Also make sure to have a wood backing plate to keep the mandrill from walking to get a cleaner hole. Clamped in a drill press works best but a hand drill works.

 

[Ron B.]

Not all stainless is the same. Have you checked to see if the stainless will affect the compass?

 

[Mike S]

Also make sure to have a wood backing plate to keep the mandrill from walking to get a cleaner hole.

Just drill the pilot hole then stop, and either change the pilot drill bit for a smooth rod, or sometimes you can extend the pilot bit or reverse in in the holder------however you do it, get a smooth pilot going prior to letting the outer cutting device start cutting the final size hole.

This works for both fly cutters and hole saws.

Wood block backing and drill press are also good suggestions.

 

[Steve Crewdog]

Not all stainless is the same. Have you checked to see if the stainless will affect the compass?

Whoa....

 

[D-Dubya]

Depending on the grade, some stainless steels are magnetic. Wouldn't recommend it for anything around a compass. And stainless steel is usually harder than hammered cat turds. Better and easier to go with good ol' aluminum.

 

[Steve Crewdog]

The punch is assembled backwards, with the cutting edge pointed away from the female side. If that's truly the orientation you used, that's why it only folded the metal instead of cutting.

View attachment 120874View attachment 120875

Ok, everyone, time for me to eat a big humble pie, I made a huge mistake.

Earlier today Member hgerhardt posted that I has assembled the punch wrong. I posted in reply that I was cutting a 2 1/4 hole for a compass and that bit was inside. But my Spideysense was going off, and I went and retrieved the punch. hgerhardt was, indeed, correct. It turns out that there are different "receiving" sides for the punch, and knowing just enough to be dangerous I used the wrong side for the receiving end. I just assembled and used it correctly, and it worked fine.

I apologize to hgerhardt, and to any others who read my now deleted post replying to him. I was wrong, and if used correctly, the knockout punch will work on stainless steel just fine.

Plane and Simple

Instrument holes—they're easy and fun with the right tools. By Jon Croke.

www.kitplanes.com

 

[D-Dubya]

Better to figure that out on a piece of scrap than a nice, shiny instrument panel blank!

 

[Steve Crewdog]

Now the fun part: getting the blank out...

 

[Mike S]

Now the fun part: getting the blank out...

Turn the die over, should be a hole where you can drive the plug out.

 

[Steve Crewdog]

Turn the die over, should be a hole where you can drive the plug out.

so THAT'S what that hole is for! (I used a Dremel to cut it into a couple pieces and took it out.)

 

[wirejock]

Why stainless?
Just curious. Why not use aluminum or fiberglass? Both non ferrous.

 

[Steve Crewdog]

Why stainless?
Just curious. Why not use aluminum or fiberglass? Both non ferrous.

Scrap I had laying around, already bent, and thin and strong. Other scrap I have is .063 at least.