Frozen Set Screw

[Steamdragon]

While disassembling my Mark VII (original) I managed to strip out the head of one of the set screws. As I have done before I tried to drill it out only to discover the set screws are pretty damn hard. Now I have a set screw that is partially drilled out. Any suggestion how to get it out?

[dusty]

While disassembling my Mark VII (original) I managed to strip out the head of one of the set screws. As I have done before I tried to drill it out only to discover the set screws are pretty damn hard. Now I have a set screw that is partially drilled out. Any suggestion how to get it out?

I had this happen with a tapered set screw in the miter gauge bat. I began with a small drill and worked my way up. To avoid destroying the threads in the miter bar I stopped and picked the remains of the set screw out with a dental tool (an awl).

[everettdavis]

I have had some success by taking a long allen wrench and heating it up with a torch to red hot, then inserting it in the remains of the stripped screw. The heat transfer to the screw can help break up the siezure.

When drilling them out I also have found a set of left hand taps (not a screw extractor) can tap left hand threads inside the allen screw and get it to move during the process of tapping.

worst case, I once tapped one LH, inserted a long left hand thread screw, placed a lock nut on the threads, then slid a metal stand off on it, then screwed it in, slid down the stand off to touch the set screw, and locked the nut against that, right on top of the set screw remains, jamming it.

I then unscrewed the allen cup point setscrew by the left hand screw jammed against it.

That takes some time to get done, as many don't have LH taps on hand in the right size. If you have to buy the tap, get a fine thread to get the most surface of the threads in the hole you drilled. Make sure you use the right number drill, and plenty of thread lube to cut those threads.

Everett

[robinson46176]

I have a set of left hand drill bits that will usually back out a broken stud or cap-screw but as mentioned a lot of Allen head set screws are really hard. Just have to take your time and be prepared to call it names...


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[alohacnc]

Any luck?

Which set screw. And which Mark Vii. I have the old one that had the reversing motor and the ability to tilt both ways. I just refurbished mine and found a stuck set screw but it was purposely seized. I forget which one. But with any set screw you just have to drill the sucker out. Use a cobalt drill over the usual HSS drill bits you find at Lowes. Sometimes you can get lucky and hammer a larger (disposable) Torx bit in to a stripped allen head.

[JPG]

Any luck?

Which set screw. And which Mark Vii. I have the old one that had the reversing motor and the ability to tilt both ways. I just refurbished mine and found a stuck set screw but it was purposely seized. I forget which one. But with any set screw you just have to drill the sucker out. Use a cobalt drill over the usual HSS drill bits you find at Lowes. Sometimes you can get lucky and hammer a larger (disposable) Torx bit in to a stripped allen head.

????? Which one ?????