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I own a Bosch GSR cordless screwdriver/drill. This drill automatically locks the spindle so that it can be used as a passive screwdriver, e.g. if the battery is empty (that's what the manual says).

Sometimes I use it to screw climbing holds to a climbing wall (using M10 threaded screws). However, even the drill setting on the slow gear doesn't provide enough torque to fully fix larger holds, so I currently use an allen wrench for the final (half) turn.

Can I use the cordless drill in "passive mode" for this final turn, or will I damage it? If so, would it be better to release the trigger and then turn the drill, or should I fully press the trigger while turning it?

I could imagine that the latter would lead to overheating, but this is only for a few seconds. But I guess the first option would probably lead to torque that is larger than the drill is designed for.

Additional info: On a climbing hold manufacturer's website, I read that the holds should be tightened with a torque between 35 and 45 Nm, while Bosch lists a maximum torque of 30 Nm for my drill.

  • P.S.: I hope my question and the title are clear and understandable, I'm not that familiar with the terminology. Feel free to ask for clarifications and/or suggest improvements! Also, I hope that this is the right site for this kind of question. outdoors.SE might have been an alternative due to the relation to climbing route setting, butI think this is the best place for asking about power tools. – anderas Jul 25 '16 at 12:56
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    Buy a carpenter's belt - looks kinda like a BatmanUtilityBelt. Then you can bring a bunch of tools with you; no need to hold them in your hands. – Carl Witthoft Jul 25 '16 at 15:09
  • Btw. Have you checked if the climbing holds require a specific torque? I have seen some, and in that case you need a torque wrench anyways – PlasmaHH Jul 25 '16 at 17:57
  • Thank you for all the useful suggestions! But I know that I could simply use a manual wrench, and that there are ways of carrying both tools. Yes, there are better tools for the job (and, in fact, they are only a few metres away), but once in a while "mis-using"(?) the tool would be the easiest way. I only want to know if I'll damage my tools by doing this ;-) (I also know about the risk of dropping things while screwing in a climbing hold one-handed while dangling under an overhang with the other hand ;-) ) – anderas Jul 25 '16 at 19:54
  • I wonder if an air wrench would be a good idea. Air tools are usually fairly light compared to cordless ones, and depending on the height of the wall it might be less of a problem to get air tubing up there (or even drop it from above. – Alan Shutko Jul 26 '16 at 2:58
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You can but it would be easier and more efficient to bring a manual wrench. A wrench or ratchet will let you apply your torque closer to the same plane as the head of the bolt. Turning the drill will be like a ratchet with an extension on it. Use the right tool for the job, your tools, your watch, and your wallet will thank you for it!

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    I know that a manual wrench would be easier in general. But sometimes simply using the drill makes the difference between using a tool in a slightly awkward way and down-climbing 2 metres (while holding the drill with one hand), changing tools and climbing up again because I'm too lazy to take a ladder to fix two holds ;-) – anderas Jul 25 '16 at 13:26
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    I haven't been climbing in a few years. Is it possible or practical to just take your tools with you? Bucket on a rope or a few important tools on a leash will equip you to deal with what you may happen to notice while addressing a different problem. – Freiheit Jul 25 '16 at 13:37
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    Also, are there tourque specs for these bolts? Taking up a tourque wrench so that you can say for certain a bolt was tightened to at least X-ft/lbs or Y-N/M may add a layer of safety to ensure holds are not going to back out. – Freiheit Jul 25 '16 at 13:38
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    This is only for a really small bouldering gym, so there is no rope involved. Sometimes, there are only two or three holds to be fixed that I can't reach while standing on the ground, so that taking the ladder from storage would be overkill if there are really easy routes set up close. RE the torque specs: I know of no universally applicable ones, since that would depend on the hold size. For really small holds, my drill is enough, but larger ones would spin if I didn't tighten them more. So basically my question is realls "Is it ok?", not "Are there alternatives" ;-) But thanks! – anderas Jul 25 '16 at 13:44
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    @Freiheit: Well, for the purposes of construction, I assume one can add some garment with pockets. – wallyk Jul 25 '16 at 16:31
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Yes, you can use the driver in "passive mode" for your final turns. It is better to avoid holding the trigger during these turns, because while you're holding the trigger the driver's motor will be energized. As the motor is no longer providing sufficient torque to turn the screw, this energy is being wasted. At best it's wasting power, and at worst it's creating heat and wearing down your motor.

Also if you want a power tool that can provide higher torque for fastening screws, try an impact driver.

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    Thanks for the answer! Do you have any links to "authoritative" sources, or is this considered common knowledge? I'm asking because the torque would be greater than the maximum torque of the motor and fearing that the "lock" might not be designed for that case... – anderas Jul 25 '16 at 13:28
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    Yeah, it seems to me that if you're cranking on the tool with significantly more force than the motor can provide you're running the risk of damaging gearing, etc. It's something I've done to a mild extent, but this particular case sounds risky. – isherwood Jul 25 '16 at 14:32
  • +1 for impact driver. Couldn't imagine life without one! – Jamie M Jul 25 '16 at 16:43
  • It's good question, but I don't know where you'd find the max torque that the driver's lock would be designed for. My guess is that it should be able to handle what a strong human can produce with their hands on the tool, as Rory Alsop states in another answer. But I agree with others that if you're regularly doing this you'd be better off with a wrench. Or switch to an impact driver and be happier. :) – Shimon Rura Jul 25 '16 at 16:49
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Having the tool locked is abslutely fine - it's not a 'maximum torque' issue - well, at least until you get up to very high torque!

The spindle lock is going to be able to cope with more torque than you can manually apply. This doesn't mean you can add a lever arm to it - that would be a bad idea - but don't be afraid to crank on it when locked.

As mentioned by Shimon, don't use the trigger at the same time (you shouldn't do this anyway when the spindle is locked)

  • I'm just not convinced about your claim. The lock may indeed be strong enough, but split-housing drill chassis tend to begin to deform under that much stress. I'm not that big of a person and I believe I could crack (or at least deform) a typical drill case. – isherwood Jul 25 '16 at 18:16
  • I'd be impressed if you could. How much torque do you think you can create? I have really yanked these things, and in a much better propped position than halfway up a wall. – Rory Alsop Jul 25 '16 at 18:24
  • I'm sure they vary by model. Obviously newer models are built for more torque, and presumably have more robust chassis. – isherwood Jul 25 '16 at 18:38
  • @isherwood I just read on a climbing hold manufacturer's site that the final torque should be on the order of 35-45 Nm, while the maximum "active" torque of the drill is 30Nm. So the difference shouldn't be too large, at least for smaller holds. – anderas Jul 25 '16 at 19:58
  • Fair enough. You might edit to reference the recommended fastener torque rather than what a human can impart. – isherwood Jul 25 '16 at 20:18
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You're looking for a very specific use. You're on a wall face, and you're trying to adjust some holds. I get that it's important to be able to do this one-handed, with a light weight "screw gun", but it seems like you're using the wrong tool for the job. I'm not going to tell you to get a wrench or impact drill though.

This is one of those cases where you should just get the specialized tool, or machine one yourself. Something like this "wrench" will save you a mountain of time on that final turn, but isn't pleasant for the first 40 turns.

This handle will work wonderfully to swap between your drill and hand tightening. If you have no other choice this may be a way to go.

But I would suggest looking at This comparison and finding a driver that has more power but is still light weight enough to work with.

If all else fails, or you're just not fining a driver that is comfortable to use, then this ratcheting handle way be the best option.

But using your drill in "lock mode" will typically wear it out pretty fast. I have ruined 4 or 5 this way, simply because the plastic handle gives way. It's good for a "quick fix" but long term use, specially in an environment where it will be really easy to put your weight onto the handle, is asking for problems.

  • Thanks for sharing the experience that you ruined some this way! What model/class were they? This is the answer that actually convinced me to try a utility belt or another way of carrying the both the drill and wrench that I'm currently using for the final turn, though my question was really not about alternatives. We HAVE wrenches like the one of your first link, but I'm interested in whether I'll harm my driver if I use it like that once in a while. – anderas Jul 25 '16 at 19:44
  • (BTW: I think the GSR 10.8-2-LI is more powerful than all or most of the drills in your comparison, I wouldn't even have thought about trying that with a weaker one.) – anderas Jul 25 '16 at 19:47
  • @anderas they were cheaper ones, for sure. They locked as you describe, and the locking mechanics would work fine, but the handle would end up damaged. The thing to remember is that your hanging from a wall, and the only real way you can apply torque to the driver is to shift your weight so your basically "hanging" on it. Not that you would fully, but it's not like it's on a work bench either. So to apply 20 lbs of torque you have to shift 10% of your weight. Well, what if your shift 30% by mistake? – coteyr Jul 25 '16 at 20:10
  • I'm thinking of accepting your answer for pointing out that the handle might be a weak point. However, the handle in the second link would be useless for me (doesn't look like it could be used to comfortabls tighen something to 40Nm), and the drills in your comparison link are even weaker than mine. So they would basically be useless to me or anyone setting climbing routes. If you could improve your answer in that aspect, I'm going to accept it unless somebody with more specific knowledge posts one :-) – anderas Jul 27 '16 at 7:19

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