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What technique do I need to use for drilling out a steel screw? Might be stainless, not sure.

I'm using a Milwaukee M18Fuel hand drill and Milwaukee cobalt bits. It's a powerful drill.

I've made a mark with a center punch and am using a moderate amount of pressure. I drill for ~10 seconds and let the drill rest for 20. I put a drop of thread cutting oil on the screw every other time. I'm using the slower "1" setting on the drill. Problem is, it seems to be taking FOREVER and I'm not sure if I'm doing something wrong. Don't want to damage the drill or destroy all my bits.

BTW, I've tried everything before deciding to drill the screw but everything failed: impact driver, impact screwdriver, vice grips, all the stuff that gets repeated on the web. Nothing worked. The screw is stuck. I think this is a self-drilling screw. This is to gain access to a junction box that the previous homeowner screwed shut for some unknown reason. Don't care about damaging the junction box cover.

Thanks

Dan
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A few techniques I've used successfully and depending on the materials and geometry of the situation.

-For the hardest materials, grinding is better than drilling (stainless steel is pretty hard to drill)

-Use a Dremel tool to cut a slot in the broken fastener shank and then use a screwdriver to back out the broken off fastener

-Use a Dremel tool with an appropriate burr or grinding type bit and grind out the broken off fastener; you will likely have to re-tap the hole before reusing

-Remove enough of the broken off fastener and then perhaps the retained cover, and then use vice grips to back out the broken off fastener

-(For softer metals and relatively larger diameters) Use a left-handed drill bit and sometimes the fastener will back itself out while drilling. If not, after drilling to a depth of about 3x-5x the bit diameter, use an appropriately sized screw extractor - be VERY careful so as to not break off the extractor since its hardness is very hard and almost impossible to drill

-I haven't tried this myself since I don't have welding equipment, tack a donor bolt to the broken fastener and back it out

Be prepared to buy multiples of the grinding items as they will be consumed.

coderjohn
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