Drill baby drill. Or give up, hire a contractor. Whatever.
September 22, 2012 4:33 PM   Subscribe

Can you take a guess why I'm having trouble drilling? Surprisingly long!

I've been doing, not hugely successfully, a lot of drilling lately. Maybe my drilling always had a 50% success rate, and I just never noticed because in total I wasn't doing much of it, but now I am and I'm seeing my failure rate.

I have a Ryobi something, a Dewalt something, and some old little Black and Decker thing. Mainly I use the Ryobi. I use it on full charges.

Typically, I can drill a little and then hit a point where I can't go further. A typical thing is trying to hang braces for shelves. Whether I drill for a pilot hole or use the screwdriver bit to drive a Phillips head screw into the wall, it will go for a bit (let's say an inch) and then slip and start stripping the screw and I'm left with half of it hanging out and a thhhpt thhhpt thhhpt sound as it strips the screw.

I use a magnet-based stud finder, which seems to work pretty great. I don't think I'm drilling into nails behind the wall (over and over?)

I'm not doing anything weird, I swear. I'm not trying to stick a thumbtack into a brick. The house was built in 87 and I think it's pretty much just normal, all-purpose, vanilla walls. The screws do tend to be longish (1.5" to 2") and sold as 'wood screws' but I've used a lot of different types in desperate attempts.

I have a variety of screw drill bits, a bunch of #2s that I just bought new in hopes of fixing this problem, a #3, both the snubby indentations and the sharpish indentations and yet here I am. I have played around with speeds and torque which I don't fully understand. Which, uh, might be a clue.

I do pilot holes. Last week, I was trying to drill some pilot holes and kept getting the bit stuck when I reversed. I had to ease it out with pliers.

I am a woman, but I am not Tyrannosaurus Rex--I don't think strength is the issue. My hands are kind of small but overall, lack of strength isn't something I'm struggling with in other areas of my life.

What the hell is wrong with my drill habits? Can you help me up my game and develop a better understanding of how this works?
posted by A Terrible Llama to Home & Garden (35 answers total) 2 users marked this as a favorite
 
Sorry if this is obvious, but are you using the correct type if drill bit for the wall. Masonry drill bits are different to wood drill bits and they are both different to glass drill bits.


I drill in slowly, then in and out. It helps release the detritus formed by the drilling.
posted by taff at 4:41 PM on September 22, 2012


I should add, it's possible I have a poor understanding of how to match screw drill bit size to screw--typically, I just sort of go by eye.

It is the first time in my life I've ever had to pay much attention to screws other than in the sense of 'Is this object a screw? If so, find one that's sorta the right size and looks okay and use it'.

Now I am learning about masonry screws and wood screws and that screw bits have sizes.

Not that I'm necessarily using the right ones but I'm at least aware now that the distinctions exist. So progress?
posted by A Terrible Llama at 4:41 PM on September 22, 2012


Metal studs?
posted by Mr. Yuck at 4:41 PM on September 22, 2012 [1 favorite]


I should have previewed -- but I think I am. The drill bits are all purpose (the standard ones that come in the kit with the drill). The screw drill bits, I think in this case, are all purpose as well.

Although I did get some masonry drill bits out of desperation when I couldn't drill through the wooden floor of an old flowerbox -- which also didn't work, though I think the wood had fossilized and might be producing fuel.
posted by A Terrible Llama at 4:42 PM on September 22, 2012


I think you mean snubby to be masonry. And sharp to be wood drill bits ... is this correct?
posted by taff at 4:42 PM on September 22, 2012


I think I am using the proper bits.

I will be quiet now.
posted by A Terrible Llama at 4:43 PM on September 22, 2012


When the drill goes in only so far and then stops, is it stopping suddenly as if it hit something impenetrable, or is it just meeting a lot of resistance that you could push through?

One thing to keep in mind is that drill bits don't make material disappear. Drills have 2 little cutting edges on the end, and the material they cut away has to go somewhere. It goes into the spiral flutes along the length of the bit. When the hole is shallow, the material can find its way back through the flutes and out of the hole, but when the hole gets deep the material gets packed tightly in the flutes and bit stalls, so you have to pull the bit out, clear the flutes, and then resume drilling.
posted by jon1270 at 4:43 PM on September 22, 2012


If you're drilling into studs, you definitely need a complete pilot hole. Also keep in mind that the pilot hole's diameter should be equal to the "valleys" of the threads on your screw.

/\__/\__/\ (the valleys would be the flat parts here)
__ __ _
\/ \/ \/

The fact that your pilot drill bit is getting stuck leads me to believe that there's something else going on behind the drywall, such as masonry. Any indication that that's the case? Are you seeing sawdust come out, or just white powder?
posted by ShutterBun at 4:43 PM on September 22, 2012 [2 favorites]


Also, is your drill going in forward, reverse or hammer?
posted by taff at 4:44 PM on September 22, 2012


Is this wall the outside of the house or a load-bearing wall (runs a long distance)? If so, you might be seeing strapping over a masonry wall. A cement brick would behave as you describe.
posted by bonehead at 4:44 PM on September 22, 2012


It sounds like the bit is "camming out"? This happens more often if you're using the wrong size bit for the screw, but it also happens more often if you mix Philips and Pozidriv screws/bits— they look almost identical, and are designed to be mostly compatible, but the right kind of bit does fit better. So if you're having this problem maybe try to match that. Unfortunately a lot of stores aren't really clear on what they're selling.

You might also try Robertson screws (the kind with a square indentation in the head); I've found them to work really well for screwing into hard wood, especially if I'm having a hard time putting enough pressure on the drill to prevent cam-out. Spend an extra couple dollars on the higher quality screw bit, it does make a (small) difference.
posted by hattifattener at 4:44 PM on September 22, 2012 [1 favorite]


Oh, and when the drill bit stops going in easily— pull it out and look at what's on the tip. If you see masonry dust or curls of metal instead of sawdust, you know what the problem is.
posted by hattifattener at 4:46 PM on September 22, 2012


Snubby versus not stubby

The experience is happening on both internal and external walls, and on the floor of an ancient wooden flowerbox (in that case I was trying to drill drainage holes.)

So it happens when I'm both screwdriver-drilling and drilling....in the drilling scenario, in the floor of the flowerbox, rather than camming out because there was no screw involved, it went in about half an inch then spun and spun.
posted by A Terrible Llama at 4:49 PM on September 22, 2012


it went in about half an inch then spun and spun.

*What* spun and spun? Do you mean the drill was spinning but not going further in? With the drill (but not with the screwdriver bits) I'm starting to suspect that you haven't tightened the drill chuck sufficiently.
posted by jon1270 at 4:53 PM on September 22, 2012


Your bit is loose in the chuck, I think.

Tighten it up.
posted by jamjam at 4:55 PM on September 22, 2012


Hmm, also, some power screwdrivers have a kind of torque-wrench-like setting so that they'll start slipping (internally, on purpose; there's a clutch you can adjust) once the screw becomes too hard to turn. The idea is that you set it so that it slips after the screw is fully driven in but before anything starts to strip. Is it possible your screwdriver has that and it's set 'way too low?
posted by hattifattener at 5:06 PM on September 22, 2012 [1 favorite]


LIke hattifattener say above, you'll know that the torque thingy is set too low if you hear it make a clattering/buzzing racket and it stops turning.

If you're having a hard time tightening up the chuck sufficiently, switch to hex shank bits. (but avoid the super cheap ones)

Also, when you're driving a screw, it'll go in WAY easier if you first rub the screw threads on a bar of hand soap.
posted by bonobothegreat at 5:10 PM on September 22, 2012 [2 favorites]


Any decent drill should be able to drive a 2" wood screw up to #10 into a standard Pine or Spruce stud without predrilling. If for some reason your studs are fir or a hardwood that might explain the difficulty your are having. Fir especially is notorious for getting harder as it ages in a random factor. A 30 year old fir stud can be so hard that nails from a pneumatic driver won't penetrate full depth.

One thing to look at is technique. You need to keep your screwdriver bit in line with the screw. If a line drawn parrallel to the bit isn't parrallel to the screw the bit won't grip properly and will cause excessive cam out.

hattifattener writes "You might also try Robertson screws (the kind with a square indentation in the head); I've found them to work really well for screwing into hard wood, especially if I'm having a hard time putting enough pressure on the drill to prevent cam-out. Spend an extra couple dollars on the higher quality screw bit, it does make a (small) difference."

Be aware there seems to be two Robertson "standards"; I'm guessing a Canadian and a Chinese. One of them is ever so slightly smaller than the other and you can buy screws and bits in both sizes. Sadly they aren't labelled in anyway because they are supposed to be the same so a certain amount of trial and error with different bits from different sources is required but if you are experiencing excessive cam out with Robertson's try changing your bit.
posted by Mitheral at 5:17 PM on September 22, 2012


Since you're getting a lot of advice that assumes you are having a lot of different issues, I will start by asking one question: do your screw heads end up looking like this or worse?

If yes, it is [likely] an issue of technique. Keeping both axes of the driver bit parallel with the screw is harder than just the one that some [like me] usually keep an eye on. This can also be helped slightly with the soap-on-the-threads suggestion above.

If no, then somebody else can ask a clear diagnostic question about their own idea.
[I'm off for the night]
posted by Acari at 5:44 PM on September 22, 2012


impact drill?
posted by couchdive at 7:34 PM on September 22, 2012 [1 favorite]


Impact Driver is what you are after. If you start to strip the heads with an impact driver, don't overdo it, stop, find a broad rubber band, put that between the screw head and the driver bit. Also woks for taking out stripped heads.
posted by iamabot at 7:57 PM on September 22, 2012 [2 favorites]


Screw bits (flat, Allen and Philips are the common ones) wear out. You say you're stripping screws, but every time you do, you wear down the screwdriver too. And a worn-down screwdriver is more likely to slip out of the screw head, then your drill spins up and the two parts wear each other down.

I'd suggest buying some new bits, and try them with new screws. You have to press pretty hard when you're using an electric drill to screw into 2x4 wood, but you're not pressing to push the screw in faster, you're pressing to keep the bit in the screw head.
posted by spacewrench at 9:10 PM on September 22, 2012


Let's get this right - it's not drilling you're having problems with, it's screwing?

You seem to be reporting problems with getting the screw driven fully in? And you're using your drill tool with a screwdriver bit attached. Ok - don't worry, it happens to us all.

The only tips I can actually offer are:
- use the correct screwdriver tip
- keep the drill tool lined up directly behind the screw and apply lots of pressure
- try to do it all in one go (seems to me that once I stop and re-position etc, things start to go wrong)
- do drill a pilot hole and make sure it's as long (deep) as the screw, but much thinner

Good luck.
posted by Xhris at 10:00 PM on September 22, 2012 [1 favorite]


To size the drill bit for the pilot hole; hold the drill bit (out of the drill) lined up with the screw, right together, sides touching. Look at the solid part of the drill bit. It should be the size of the "shaft" part of your screw (like shutterbun said). Close one eye and put the drill in front of the screw, and then switch.

You need a bunch of screwdriver bits, one is not going to fit all screws. Buy one of those assortments of bits. Hold the screw up and fit it into the bit. Wiggle it around and twist it. It should fit very tight. If it moves at all when your holding it it will almost certainly strip out. It will work until it starts to get warm and the pressure gets higher.

As everyone said, make sure you are holding the drill straight into the screw.
posted by bongo_x at 10:07 PM on September 22, 2012 [1 favorite]


*What* spun and spun? Do you mean the drill was spinning but not going further in? With the drill (but not with the screwdriver bits) I'm starting to suspect that you haven't tightened the drill chuck sufficiently.

The drill bit spun and spun.

If it's that I haven't tightened it sufficiently...I don't know how to do that, other than to just tighten it until I can't tighten it anymore, which might be insufficient but I don't know how to do that better. If that's the case, I need some kind of trick because arm strength alone won't do it.


Also, is your drill going in forward, reverse or hammer?

Forward in all these scenarios -- reverse typically goes okay when I'm doing things like removing short screws. On occasion, like with the flower boxes, it will get stuck on the way out but those were a thousand years old and maybe fossilized.


Hmm, also, some power screwdrivers have a kind of torque-wrench-like setting so that they'll start slipping (internally, on purpose; there's a clutch you can adjust) once the screw becomes too hard to turn. The idea is that you set it so that it slips after the screw is fully driven in but before anything starts to strip. Is it possible your screwdriver has that and it's set 'way too low?


It is *totally* possible. I think this is the drill. I believe the adjusting bands refer to torque and speed. Unfortunately, I'm not overly clear on how those things can Work For Me.

If you're having a hard time tightening up the chuck sufficiently, switch to hex shank bits. (but avoid the super cheap ones)

Also, when you're driving a screw, it'll go in WAY easier if you first rub the screw threads on a bar of hand soap.


On the first, wow, that's a thing? Can I use those with the Ryobi?

And on the second, that is absolutely something I can do.

You have to press pretty hard when you're using an electric drill to screw into 2x4 wood, but you're not pressing to push the screw in faster, you're pressing to keep the bit in the screw head.


This is a good distinction.

I will try as many of these suggestions as I can today. Today, unfortunately, I face a lot of drilling and screwing and I'll take this opportunity to decline to make any dumb jokes.

I do use the verbs nearly interchangeably but mainly what I am doing is 'drilling for the purposes of a pilot hole and then following by screw-drilling to insert a screw'. The threads on the drill bits I use for pilot holes don't seem really deep enough for some of the lengths of screws I've been using. I've always thought of pilot holes for depth and to keep things tidy on the surface so things don't split, but I'll try to make sure I'm doing deep enough pilot holes.

The drill has a level at two points on it so you can make sure you're drilling straight and not coming in at an angle but it's possible I'm paying only intermittent attention to it.

Thanks everyone.
posted by A Terrible Llama at 4:16 AM on September 23, 2012


For purposes of clear communication, you should scrap the term "screw-drilling." Holes get drilled. Screws get driven. So, you're having trouble both when drilling holes and when driving screws. Similarly, The threads on the drill bits I use for pilot holes" makes no sense. Drill bits don't have threads, they have flutes, and the distance they are cut along the length of the bit has nothing to do with how deep a hole they can drill.

The drill bit spun and spun.

If you're sure that the bit itself was turning, then chuck tightness wasn't the problem. The idea that you aren't getting the chuck tight stems from a guess that maybe the bit had stopped turning even as the chuck kept going round and round. But for the bit to keep turning, with you putting pressure on it, and not cut through the material, is really unlikely. Drill bit steel is much harder than any wood. Unless you at some point made that drill bit hideously dull by running it into something very hard and abrasive like a cement block or a brick or the sand-filled plaster in an old house, it WILL cut through any wood in the world *if* it's actually turning and you're putting a little pressure on it. Especially with smaller drill bits, it can be hard to tell when the chuck is loose and starts to slip, so look closely and be sure you're seeing what you think you're seeing.
posted by jon1270 at 5:17 AM on September 23, 2012


Just coming back to say that the fastest way to deal with this problem might be to demonstrate for someone IRL. It's a great excuse to invite somebody over for a beer.
posted by bonobothegreat at 11:09 AM on September 23, 2012


I use a magnet-based stud finder, which seems to work pretty great. I don't think I'm drilling into nails behind the wall (over and over?)

If you're drilling _exactly_ where the stud finder indicates, then it's possible that you're drilling into nails every time. That's how a magnetic studfinder works -- by locating the nails and other ferrous items attached to the studs. If you're drilling an inch or two below, then probably not.

I think this is the drill. I believe the adjusting bands refer to torque and speed. Unfortunately, I'm not overly clear on how those things can Work For Me.

I'm only seeing one thing there that I'd call an adjusting band -- the part with numbers in a yellow ring, which you can rotate by turning the silver part. There should be a mark somewhere on the blue part near the yellow ring, probably a triangle, which indicates which number is being selected. That ring controls the torque. Torque is a measure of how much power the drill will put into rotating the bit before it slips internally, protecting you from either stripping a screw head or from kickback of the drill body should the bit become stuck in the wood. High torque means it will have to get stuck a lot harder before the clutch slips; low torque means it will slip more quickly. In practical terms, you'd use lower torque to drive smaller screws or drill smaller (diameter) holes, and higher torque to drive larger screws and drill larger diameter holes.

Are you considering the black section between the silver section and the tip of the drill to be another adjusting band? Because that's the part which opens and closes the chuck jaws, and controls how tight a grip the chuck has on the bit. There's also that yellow part below the "Ryobi" logo with a black triangle on it. That's the part which controls the direction the chuck turns when you squeeze the trigger. It slides left and right, and if it stops in the middle then it has probably locked the trigger to prevent the drill from turning at all. When that happens, you can turn the black part to open and close the chuck jaws. You want them to be closed as tightly as possible when in use.

Speed is almost certainly controlled by how hard/deeply you're squeezing the trigger. If you squeeze it gently, it should spin more slowly than if you squeeze it all the way down. There may also be a HI/LOW switch on top of the drill which modifies the range of speeds the trigger controls. HI will start off faster and end up much faster, while LOW should start off slowly and end up (with the trigger squeezed all the way) pretty fast, but not as fast as if the switch is set to HI. If you have that switch, you probably want to use LOW for driving screws and HI for drilling holes.

For drilling holes, you want to start off relatively slow until the bit catches and starts cutting the wood, then you can go faster. I only ever use high torque for drilling holes, but if you're using tiny bits, you might want to use lower torque so you don't snap the bits if they get bound up. For driving screws, you want to start out slow and not go too fast, until you're familiar with how to adjust the torque so you don't have such high torque that you either strip the head or drive the screw down into the wood, but don't have so little torque that it fails to drive the screw all the way.

in the drilling scenario, in the floor of the flowerbox, rather than camming out because there was no screw involved, it went in about half an inch then spun and spun.

For clarification, were you applying downward pressure (in the direction the drill bit was pointing) while this happened? Because a drill bit, unlike a screw, will not pull itself through material by its threads (which, in the case of a drill bit, aren't threads at all). You have to push it through. If it gets stuck, you should be able to free it by pulling backwards while squeezing the trigger. (You should do this periodically anyway, to clear compressed bits of wood out of the flutes of the bit.) You shouldn't have to switch the direction the bit is turning for this; it should pull out while you're spinning it in the clockwise drive-the-screw-in direction. If the bit stays in the wood and slips out of the chuck jaws, then you're definitely not tightening the chuck enough.

Without photos or video of what's going on, it's hard to say what the problem might be. Do you have a way to take a video of yourself trying to drill through the flowerbox floor, for example, so we can see what's happening?
posted by hades at 1:03 PM on September 23, 2012 [1 favorite]


The threads on the drill bits I use for pilot holes don't seem really deep enough for some of the lengths of screws I've been using.

This sentence confuses me. Do you mean the drill bit isn't long enough for the length of screws you're using? If that's the case, you need to buy longer drill bits. The drill bit should be just about the same circumference as the shank of the screw between the threads. The pilot hole removes just enough wood to drive the screw without clogging the threads with wood bits, and to allow enough remaining wood around the hole for the screw threads to bite. If you're making proper size pilot holes, you should be able to drive the screws in without a hitch. If you are using things like drywall anchors you mach the drill bit size to those.

For the flowerbox, were you unable to drill a pilot hole with a new wood bit? Were you trying to use a bit that was already the size of the hole you wanted? The way I do it is to put the wine barrel or whatever on top of a piece of scrap wood, drill a pilot hole, and then turn it over and gouge a big hole with a spade bit.


The screw drill bits, I think in this case, are all purpose as well.

Screw driver bits are sized for specific screws. The picture you posted looks like #1, #2, and #3 philips driver bits. Your screws should say on the box what type they are. You will save yourself numerous headaches by using the proper screw drivers for the screws you're using, and by tossing the worn drivers if you've stripped a bunch of screws. When you're not some burly huge person you can't brute force things- take the time to buy the correct bits for the material you're drilling, drill the correct diameter and length pilot hole for the screws you're using, and drive he screws with the appropriate screw driver bit. Everything will work together as it should and be that much easier. This will also eliminate a bunch of questions as to what's going wrong in your scenarios and make it easier for people online to troubleshoot.
posted by oneirodynia at 4:46 PM on September 23, 2012


oneirodynia writes "The picture you posted looks like #1, #2, and #3 philips driver bits."

Those are actually Pozidriv bits. They have an extra pointy bit in between the main cross arms of the Phillips bit. Pozsidriv bits will sort of work with Phillips screws but aren't ideal. However it is very unlikely the OP actually has Posidrive bits as you generally have to go out of your way to buy them but rather was ignorant of the differences.
posted by Mitheral at 11:00 PM on September 23, 2012 [1 favorite]


I am an electrical contractor. We often have to drill out every stud in the new home to run wire through the house.

The one thing I would say is: use a corded drill. Battery powered drills just do not have the power for doing a lot of drilling. An extension cord might be a bit annoying, but it will make the process easier in the long run.
posted by Flood at 5:55 AM on September 24, 2012 [1 favorite]


About alignment: you mentioned using the bubble levels to keep the drill lined up, but actually that's not going to help much. Yes, it's good to try to drill the pilot hole straight, and you can use the bubble levels for that. BUT, the screw is going to go the way that it finds into the wood/wall/etc., and you can't use the driver to try to change the route that the screw has found.
All the driver does is make the screw rotate: you use pressure to keep the driver bit meshed into the screwhead slots, but it's the rotation of the screw that draws it into the material, and whatever direction the screw shaft is pointed when the teeth of the screw engage with the material, that's the direction the screw is going to go, be that straight or diagonal. Having the pilot hole is useful to encourage it to choose the direction you intended.
So, you're holding the driver, the screw has gone in half an inch or so,a nd you're off to a good start. Stop the drill for a second, and take a look. The screw's not too wiggly, but not in all the way. Is it pointing precisely straight perpendicular to the wall? For most purposes that's not a key useful/necessary thing, but it is important for you to notice. If you hold the drill pointing perpendicular to the wall, it won't work nearly as well as if you examine which way the screw is going, and line up the drill as precisely as you can on that axis. That will help the driver bit stay engaged with the screw slots and help prevent skating around and ruining the screw head.
posted by aimedwander at 8:24 AM on September 24, 2012


bonobo said: Just coming back to say that the fastest way to deal with this problem might be to demonstrate for someone IRL. It's a great excuse to invite somebody over for a beer.

This. All the words we can write may not help you as much as one on-site visit. Llama, where are you located? Want to invite one of us over? That would involve beer. Two or more, beer and pizza.
posted by exphysicist345 at 2:36 PM on September 24, 2012


bonobo said: Just coming back to say that the fastest way to deal with this problem might be to demonstrate for someone IRL. It's a great excuse to invite somebody over for a beer.

Yes. Someone could tell you all you'd ever need to know in 2 minutes, tops.
posted by bongo_x at 6:19 PM on September 24, 2012


Okay, I wanted to report back that I suck much, much, less at drilling thanks to these responses and some Memails I exchanged with Hades, one of which, with his permission, I will reprint here in order to best answer it.

I think out of fear I wasn't strong enough I was really ignoring speed, just brute forcing left and right, and when I started going gentler on the trigger, going particularly slow at the start in order to get it to 'catch', and going for short quick bursts I had fewer problems--less instances of camming out or of getting stuck one way or another. And while I'm sure it would have been fun to get somebody boozed up and demo it for me, once I really started experimenting rather than just approach it with a 'drill the hell out of that thing' or 'screw the hell out of that thing' attitude, it got easier--it helped a lot to just do it a few dozen times.

Also I bought the spade bits Hades recommended which allowed me to make a nice-sized hole in a shelf I was putting up that allowed me to dangle some electrical cords down the back of it while still allowing the shelf to lie flush with the wall, which was nice. I have not approached the fossilized flowerbox again yet, but I will work up to that. I did pull off all of my kitchen cabinet doors, paint and give them new hinges, so that's about as much drilling and screwing and drilling and screwing as I can take for at least a little while.

Thanks everyone. Hades' MeMail below.


That sounds like quite a flowerbox. Goodness. I'm not incredibly familiar with masonry drill bits, but my understanding is that they aren't as sharp as bits meant for drilling in wood (the general purpose kind that probably came with the drill). Switching to a masonry bit may actually have caused the drilling to fail for an entirely new reason. I think how a masonry bit works is that you're meant to use it with a "hammer drill", which both rotates the bit and hammers it into the wall -- the hammering action causes chunks of masonry to break up, and the rotation of the bit (which is hardened to survive the hammering) scrapes the chunks out of the hole. With a wood bit, the sharp edge of the bit actually cuts into the wood (assuming you're putting some pressure on it, but you shouldn't need to put your whole body weight into it, generally), so the rotation both cuts the wood fibers into sawdust and channels sawdust out of the hole. Using a masonry bit on wood might not be accomplishing the "cuts the wood fibers into sawdust" part, so you might just be compressing the wood fibers into the bottom of the hole until they won't compress any more.

I think there's still some confusion about speed and torque which might be getting in your way, too. The numbered ring on the drill controls torque, not speed. Torque is the amount of power that is transferred from the motor of the drill out to the bit, whether it's a screw driving bit or a hole drilling bit. Some cordless drills have a setting just past the highest number on their torque that's a little icon of a drill bit -- when you set the torque to that setting, it locks the clutch and essentially gives the drill infinite torque, which is generally what you want when drilling holes unless you're using a very small bit (1/8 inch or less, probably) and are worried about breaking it. One way to think about torque is to think of how your hand works with a doorknob (the round kind, not the lever kind). If you grasp the knob gently, you can turn it until it won't turn any more -- your hand will slip around the knob. That's low torque. If you grasp the knob very firmly, you could really wrench on the knob and possibly break it off if you kept twisting after it wanted to stop. That's high torque.

Your drill has a clutch that works like your hand on the doorknob. The motor is your arm, and the chuck (the part the bits go into) is attached to the shaft of the doorknob. Power is transferred from the motor (your arm) to the chuck (the doorknob) via the clutch, which is your hand. The higher you set the torque to, the more firmly the clutch grasps the knob, and the more power gets transferred from the motor to the bit. How this works in application is that if the torque is set too low, you won't be able to drive the screw in all the way, and if the torque is set too high, you could drive the screw all the way through the wall and out the other side. It takes some experimenting to find the right torque setting for any particular job.

With the torque set too low, it can feel like the bit is spinning and stripping the head of the screw, even if that's not what's happening. As long as the driver bit is being pressed firmly into the head of the screw, the slipping should all be happening inside the clutch.

With the torque set high enough, it can be difficult to keep the driver bit pressed firmly into the screw head. If you're leaning in and putting your weight through the drill, but it's still kicking the bit out of the screw head and stripping it when you squeeze the trigger, the problem is either that you have the wrong size driver bit for the screw, or that you're squeezing the trigger too hard.

How hard you squeeze the trigger is what controls how fast the motor turns. If you hold the drill so that you can see the bit -- away from any screws, just in the air looking at the bit -- and squeeze the trigger lightly, you should be able to see the bit turn slowly. And I do mean lightly -- the trigger should only move in towards your palm a little way. If you squeeze the trigger more firmly, so that it goes all the way back as far as it can go, the bit will probably turn so quickly it's a blur. And there's a range of speeds in between. In my experience, slower works better when driving screws. Well, not _too_ slow, obviously, but slow enough that you maintain control. At high speed, regardless of torque, it's just difficult to keep a bit in a screw.

The third thing, which is only really a factor when drilling holes, is how tightly the chuck jaws are grasping the drill bit. Drill bits tend to have round shanks (the shank being the part of the bit that isn't fluted), while driver bits tend to have hexagonal shanks. A hexagonal shank can't really slip in the chuck once it's tightened past a minimum point. A round shank can, and if that's happening then the motor will be turning the chuck just fine, but the drill bit won't be rotating at all. This is hard to see at high speed, so if you suspect it's happening, try squeezing the trigger really gently and watching the bit closely to see if it's turning or not. If it isn't, it's stuck in the wood more tightly than it's stuck in the jaws of the chuck, and pulling straight back on the drill will probably leave the bit stuck in the wood while the drill comes away. And then you need the pliers to get the bit back.

Probably the easiest way to get the bit stuck in the wood is to try to drill all the way through something thick in one go. Normally, sawdust created by the cutting edge of the bit gets routed out the back of the hole through the flutes in the bit, but if the sawdust gets compressed and jams, then you end up wedging more and more into the flutes until the sawdust won't compress any more, and binds everything together. The way to avoid this is to, a couple times for each hole you drill, keep the drill running and pull it back out of the hole. Check the flutes to see if there's compressed wood stuck in them, and tap it out or scrape it out with the point of a screw if there is. Then put the bit back in the hole, squeeze the trigger and drill some more.

It might be useful to get a piece of 2x4 a couple feet long, clamp it (or have a friend sit on it) hanging over the edge of a table or something (so you don't drill into the table) and then practice on that, both drilling holes and driving screws, to get a feel for how the drill works at different settings. At least with that, you'd know that there was no chance you were hitting a hidden metal plate or fossilized mud or something.

Oh! And one last thought, just to confuse things even more. For drilling a (drainage?) hole in a flowerbox, or other times when you need a larger hole and don't care too much about it being super precise or clean, you might want to get some spade bits, like these:http://www.amazon.com/Irwin-Industrial-341008-Speebor-8-Piece/dp/B0000EI9B0/These wouldn't be something you'd use to drill a pilot hole for a screw, or make a hole in drywall or metal -- they're for removing a lot of wood quickly, and leave a rougher exit hole than a twist bit (the kind that came with the drill). But they have a hexagonal shank, which eliminates the possibility of slipping in the chuck, and they drill right through most woods like butter. If your flowerbox is made of teak or ironwood or something like that, you're probably better off just building a new flowerbox.



posted by A Terrible Llama at 1:20 PM on October 8, 2012 [1 favorite]


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