Astro_Al Posted March 31, 2009 Share Posted March 31, 2009 I was pilot drilling some holes in a 20mm steel plate with a 3mm bit. It has snapped off flush with about 12 to 15mm of drill stuck in the steel. Any ideas as to how to extract it so I can complete the hole? Cheers, Al. Quote Link to comment Share on other sites More sharing options...
steve b Posted March 31, 2009 Share Posted March 31, 2009 Hi Al, Can you drill from the other side up to the broken bit and then drive it out with a pin punch? Another way to deal with it is to cut the piece out with the broken bit and replace with a new piece of 20mm , prep the weld joints , and weld the new piece in , then drill the 3mm hole . Its always wise to 'peck' with the drill - lift out every 3-4mm of cutting depth to clear the swarf from the flutes. cheers Steveb Quote Link to comment Share on other sites More sharing options...
hoarebag Posted March 31, 2009 Share Posted March 31, 2009 Big magnet? Quote Link to comment Share on other sites More sharing options...
white90 Posted March 31, 2009 Share Posted March 31, 2009 Tweezers into the flutes and reverse it out? Quote Link to comment Share on other sites More sharing options...
Mark Posted March 31, 2009 Share Posted March 31, 2009 build yourself a spark erosion machine al? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 31, 2009 Share Posted March 31, 2009 Puddle-weld an M3 nut to the top of it? Quote Link to comment Share on other sites More sharing options...
bishbosh Posted March 31, 2009 Share Posted March 31, 2009 A variation on Fridge's idea - drill a 3mm hole in a piece of thin plate - 3mm or so. Position the hole over the broken bit and blob some weld in. Might be easier this way to keep the plate in the right place as you weld?? Quote Link to comment Share on other sites More sharing options...
landmannnn Posted March 31, 2009 Share Posted March 31, 2009 Assuming you are using a press, have you tried following with another (better quality) 3mm bit, very slow, lots of lube? Quote Link to comment Share on other sites More sharing options...
simonr Posted March 31, 2009 Share Posted March 31, 2009 I'd just follow it with a carbide / cobalt mill cutter (slot drill) or U drill - it will make mincemeat of a drill bit. Si Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted April 1, 2009 Author Share Posted April 1, 2009 Well, that was odd. I planned to follow Steve_B's advice and drill in from the other side to punch it back out the front, but in the end I inadvertantly followed Simonr's suggestion and drilled straight through the old drill bit from the reverse side. I planned to stop when I hit the old drill bit, but the 5mm drill I used didn't even indicate when I'd got there, so I just kept going - like drilling cheese! Nice. Ta Al. B) Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted April 1, 2009 Share Posted April 1, 2009 so I just kept going - like drilling cheese! OOh, do Britpart sell drill bits now??? Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted April 2, 2009 Share Posted April 2, 2009 Al, perhaps if you can't tell which side of a piece of metal you're stood and you can 'inadvertently' drill from the wrong side, you shouldn't be allowed metalworking tools? Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted April 2, 2009 Author Share Posted April 2, 2009 ...you shouldn't be allowed metalworking tools? Mr T. Bocharger, you're right, but not just for those reasons... Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted April 2, 2009 Share Posted April 2, 2009 Hey, I can't even bolt a head on straight... and it's Turb O'Charger, my family goes back generations in County Donegal Quote Link to comment Share on other sites More sharing options...
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