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I came across the tool pictured in my collection and cannot imagine its purpose. It's a long metal pick, with sharp studs running down it in a spiral. It ends in a tip that seems to be meant to make holes. It's very sturdy.

top view tip

isherwood
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Jeremy
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  • looks like a tool for repairing holes in vehicle tires ... used to clean and rough up the puncture hole before gluing a plug – jsotola Apr 13 '22 at 15:14
  • I've seen a very similar design in fretsaw sets (https://m.media-amazon.com/images/I/81+KWRkSYdL.AC_SL1500.jpg). There's a rotating grip on the spiral. If you keep it steady, the whole tool rotates, and you can use it as a drill. I don't know if those tools are related, though. – Eric Duminil Apr 14 '22 at 06:30

2 Answers2

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I would say that it's an older style drywall saw specifically for cutting curves.

You push the tip through the drywall (hammering the blue handle with your hand or other striking tool, if necessary) to make the hole, then run the tool in and out cutting with the saw teeth on the push stroke.

Since it's round, it will easily move in any direction, so when you reach a corner, you simply apply pressure to a different side of the handle and it'll cut in a different direction.

It's probably difficult to get a really straight line, but makes it very easy to cut holes for round boxes.

Now that I know these exist, I might just have to get one!

Example pic of a drill saw and the results of its use

Ref: https://kk.org/cooltools/drill-saw/

FreeMan
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    Also known as a "drill saw", and not just for drywall. – isherwood Apr 13 '22 at 13:03
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    Cool, indeed! I edited to add a picture. Please re-edit if needed. – P2000 Apr 13 '22 at 14:00
  • Is or was there a drill bit like that you use in a powered drill? Think I remember ads for it years ago. – crip659 Apr 13 '22 at 14:18
  • Any reason why it'd be so long? Drywall is only 1/2" thick generally. Most drywall saws I've seen are only a few inches. This looks like it'd go clean through the other side of the wall. I guess you could saw through the other side from the back, but I'm not sure how often you'd want to do that. – Darrel Hoffman Apr 13 '22 at 14:57
  • Thanks for the pic, @P2000! – FreeMan Apr 13 '22 at 15:06
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    @DarrelHoffman a quick look at a big-box store's web site indicates that common jab saws for drywall run between 5-8". I've always used mine for cutting the holes before installation. I think most people that cut holes once the drywall is up would use a powered Roto-Zip™ type cutter. – FreeMan Apr 13 '22 at 15:08
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    @DarrelHoffman Also, all saws work better when you can get a decent stroke length. Furiously sawing back and forth with a 2" cutting edge would be really annoying and slow. – J... Apr 13 '22 at 15:28
  • @J... 2" would be admittedly ridiculous (though I've seen those - for carving pumpkins, not drywall). I think the ones I've seen are around 4-5". Any longer and you couldn't use the full length on installed drywall anyhow, since you'd be hitting the other side. – Darrel Hoffman Apr 13 '22 at 15:38
  • @DarrelHoffman Yes, it's definitely a new-work tool. – J... Apr 13 '22 at 15:41
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    This thing is much older than drywalls - and, originally, a woodworking tool: a round drilling rasp, in German called Stichling. – tofro Apr 14 '22 at 08:17
  • Interesting, @tofro. Thanks for sharing that! I'd hate to hand drill a hole with that thing, though, the point doesn't really look sharp enough for that. Seems like it would work well enough to enlarge an existing hole, though. – FreeMan Apr 14 '22 at 13:35
  • Blades with this shape are also made for scroll saws. – Tech Inquisitor Apr 14 '22 at 16:08
  • @J... - what about when there's a stud wall that's 2" thick, and you need this tool to make a hole in only one side? Being short is then advantageous! But this one looks like the 'saw' part doesn't start for a good 2" along the end. I'd go to my hole saw at that time, though. – Tim Apr 15 '22 at 08:02
  • @Tim see this comment – FreeMan Apr 15 '22 at 11:01
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I've used one to clear the hole left in a car tyre, when the offending screw/bolt/sliver of metal has been removed. It reams out the existing hole so a mushroom plug can be put in, which then seals the hole. Not sure whether that practice is still legal all over the world, but it was a couple of decades ago in U.K.

Available in different diameters, and called a tyre reamer.

FreeMan
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Tim
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    Think you are right, but the ones I have used/seen are usually only a few inches. Could see that being used for big truck/tractor tires. – crip659 Apr 13 '22 at 11:16
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    I have one, but mine has a t-handle to make it easier to push/pull and it isn't as long. – FreeMan Apr 13 '22 at 11:40
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    Yeah, a tire reamer wouldn't be a foot long. I carry them on my motorcycles. – isherwood Apr 13 '22 at 13:02