Cutting 2" hole in 1/4" SS plate

[RichNJKubota]

Wow! Lots of good info here. Based on what I learned here I think what happened was the SS hardened. I specifically recall the moment when it happened. For this task I bought a water based cutting fluid called TapFree2. I was dripping this into the cut. Then I stopped because I wanted to get more fluid into the cut. When I put the fluid in it boiled some of it away. After that I could not cut any longer.
I turned the SS piece over to resume the cut on the other side and got in about 1/16" before I could not proceed any further.
I may try the carbide hacksaw rod to finish the cut as I don't think there's more than about 1/16" left to finish the cut.

Or perhaps heat the SS up with a torch? Will this return the metal to a softer state? I have an oxy/acetylene torch.

My drill press is running too fast even on the slowest pulley ratio. Long ago I bought this press for woodworking and it has served me well but now I'm doing mostly metal working.

I've been thinking about getting a mill do to some of these basic metal working tasks. But this is another topic all together

Up to this point I've used an oil based cutting fluid. It works great. I can see the difference in cutting speeds between no fluid and this oil based fluid.
Does anyone have a preference between the oil and water based cutting fluid?

 

[jmc]

Using your torch to anneal the hardness is worth trying. We used to buy 300 series SS round stock that came from the mill in a workharden state, for strength. One Dr wanted his pins to be more bendable. Just a propane torch on some 3/16" diameter pins worked.

 

[SPYDERLK]

Up to this point I've used an oil based cutting fluid. It works great. I can see the difference in cutting speeds between no fluid and this oil based fluid.
Does anyone have a preference between the oil and water based cutting fluid?

This one impresses me. A water base I think. Thick as honey.

https://www.amazon.com/Tap-Magic-70016T-Xtra-Thick/dp/B07CMH5GJQ/ref=sr_1_20?crid=1DOCO8RRDJQFX&keywords=tapfree+excel+cutting+fluid&qid=1670511112&sprefix=tapfree,aps,186&sr=8-20

See if you can find a way to slow down too. Maybe turn your spindle with a makeshift hand crank?

 

[big bubba]

as machinist yrs ago, i used this product esp for tapping. it may serve as a cutting fluid as well.
otherwise, you have received useful info on your post, more than i can offer. good luck

Tap Magic | Cutting Fluid | A Division of the Steco Corporation

The Steco Corporation has been involved in designing and creating the world’s greatest industrial cutting fluids since 1953.

www.tapmagic.com

 

[ruffdog]

Thin SS is more apt to work harden because the heat can't transfer away from the cutting area like it would thicker metal. We used a very black high sulfer cutting oil for cutting taps, a thick (like STP) oil for roll taps, and flood coolant for HS tool cutting.

 

[tomplum]

To hold your coolant at the cut, use some putty or a quick bead of caulk. In the circle and outside.

 

[RichNJKubota]

The TapMagic Xtra Thick did the job. Bi-metal hole saw with this fluid was slow going but it worked and gave a very nice smooth hole in the 1/4" SS plate.

The TapFree stuff that I got at the local hardware store did not work.

I drilled a hole thru the SS to let the filings drop thru the hole. But being that the TapMagic was so thick, the filings stayed on the hole saw. Had to stop every once in a while to wipe off the hole saw. It was time for a few more drops of the TapMagic anyway.

Awesome! Thanks to all for the great advice!

 

[SPYDERLK]

The TapMagic Xtra Thick did the job. Bi-metal hole saw with this fluid was slow going but it worked and gave a very nice smooth hole in the 1/4" SS plate.

The TapFree stuff that I got at the local hardware store did not work.

I drilled a hole thru the SS to let the filings drop thru the hole. But being that the TapMagic was so thick, the filings stayed on the hole saw. Had to stop every once in a while to wipe off the hole saw. It was time for a few more drops of the TapMagic anyway.

Awesome! Thanks to all for the great advice!

The drilled hole was a good idea. Came up short due the sticky fluid. To realize the advantage it would have probably just taken a metered air jet downward at the hole. Not too hard to set up next time with a regulator and blo gun.