1y ago

what is the best way to drop out a threaded screw?

So I've got some rusty old floor screws that I can't loosen with a Phillips head (they're old, so I'm betting it's not posidrv). The notches are all rusted and it hardly bites at all.

If I drill them out, I know I'm in for a hard time but am I better off going for a really fast rotation or slower?

And should I start with a narrow drill bit and work my way up (historically I've broken a few doing this in the past) or just begin at the intended diameter?

Yes, in fact I do work with computers - isn't it obvious?

18 comments

I'm assuming its a flat, countersunk screw? My usual go-to for removal where it works is to use a dremel cut off wheel to cut a slot and then use a straight bit. given the flush head, this would probably not be acceptable if you care about the wood or whatever at all.
another option is the extractor bits- the kind that are double ended. The first tip clears out any rough patches on the head into a tapered cone, the second bit bites into the cone and turns. The goal here is to get it high enough that you can get it with pliers and turn it out that way, though depending on how siezed... well, it might take it all the way out. I've never had very good success with them, though.
You might also be able to pound in a torx head bolt that just barely fits. clean it out a little, if you have working space, drop the torx bit in and set it in with a hammer (Not full on nail-swings, mind, but enough the bit bites in,) and then turn it out with an impact wrench.
- Yes counter sink screw - bang on!
  Gosh, I'd never thought of impact drivers for that purpose! Great idea. I think my only torx tools are hand-screwdrivers, give me some ideas however
  
  Be careful with the screw, going too far in drilling it out might take the head off entirely.
  If that happens you might be able to lift the wood off it, and come at it with pliers, but if the thread are in the board, that could get very… awkward.

So I'm going to assume wood floors? I'm going to note I am not a wood worker but an industrial maintenance mechanic. If you were going to drill it out I would use a left handed drill bit and a small screw extractor. I personally would see if I could find purchase with pliers, or I would weld a bit of steel onto the screw, let it cool down and go to town with a cordless drill using the welded metal as a bit for the drills chuck.
I've only been on Lemmy for about a week and have never really used social media before, if you could add a picture I'm sure that would help.
If nothing else I believe in you and have nothing but faith in you when you start battling this screw.
I am sorry for the grammar and punctuation, I was homeschooled and not very well, I'm trying to learn but I'm very slow at learning my writing skills.
- Welding would scorch the wood around it. And possibly the subfloor. Or whatever the material was
- No need to apologise for those writing skills. You write extremely well.
- Seconding the other chap. There is nothing wrong with your writing. It's a pleasure to read. Keep on writing, tinkering and giving solid advice!
- Thanks! If the worst is drilling through it and making a mess, that's kind of ok

If you don't mind buying another tool - there are unscrewing tools, which you apply like a screwdriver and hit it with a hammer. They form a new cross-slot profile in the screw head and at the same time give a rotary impulse to loosen the screw.
Anyone know what they are called?
Edit:
Screw extractor
Hand impact driver

Another tool (which I use) is a screw extractor. They come in sets, and are a conical reverse-direction screws.
You drill into the non-moving screw to give the extractor an area to purchase (unless the screw is already pretty gone), put the extractor on a drill/impact driver (the other kind), then run it in reverse until it catches.
When it does, the screw turns backwards with the drill/driver.
https://www.toolstation.com/screw-bolt-extractor-set/p51010
- Brilliant, thanks
  It'll be interesting to see how far the rust goes

Just wondering, do you need to save the floor board?
- No, I don't... It's plywood that has been under damp vinyl for far too long (there's bound to be some significant work to remediate the floor)
  
  We’ve had many of these. We just leaver up the boards and tear them out.
  You could plunge cut with a circular saw along the edge. Then work a chisel under it and just tear out the floor boards any way you can.
  Then for the screws, I either tear them out with pincer pliers for the shallow ones (you can get decent leverage with pincer pliers). Or just cut them flush with the joists and leave them there (quick work with an angle grinder and cut-off disc).
  PS. Sorry been trying to reply to you for a few hours but my client wouldn’t connect.

18 comments