Best Method To Remove a Stainless Steel Broken Screw Corroded to Aluminum Frame

[josa1]

Thanks for your inquiry and interest!

Yes, finally got the broken screws out.

After watching many videos I came to the conclusion that a drill would never work so I made a trip to McMaster Carr and purchased two plunge cutting end mills that are normally used in CNC machines.

I rigged a jig to hold the reel frame in the correct straight line position to the drill chuck which is no easy task as the holes in the reel frame holding the broken screws are drilled at an angle to the frame center line.  I made certain that the end mill went through the drilled and tapped holes of the frame from which I had been able to remove the screws
 
  I put the correct sized end mill into my drill press after setting the press to the lowest possible speed setting and SLOWLY lowered the end mill onto the broken screw.  The end mill cut the stainless steel effortlessly.  The end mill removed the screw remnants and left the threads in the frame intact.  There was a tremendous amount of corrosion but was able to clean up the threads with a tap. Probably the best part of the operation is that the end mill centers on the drilled and tapped hole. If removing a broken screw with a drill bit you have to center the drill bit on the broken screw.

Was quite a project but I had fun doing it.  It will be interesting to see how I do on the next broken stainless steel screw I run into.  But best of all I learned a very valuable lesson....

DON'T BREAK SCREWS!

josa1