Driving small sheet metal screws with impact driver?

[Darwins Child]

I've owned a 1/2" Milwaukee "Magnum hole shooter" drill for about 30 years. It still works great, but it's usefulness is limited by its size, etc.  It does not have a brake, so the heavy chuck is impossible to stop quickly, which means that it really is inappropriate for driving small screws, especially sheet metal screws. I'm looking at cordless options.   (I already own a corded hammer drill, so I do not need a hammer drill.)

 

Ideally, I'd like to buy one do-it-all tool. I now realize the advantages of impact drivers versus drill/drivers when it comes to drilling rather large holes or, especially, driving large screws.  But when it comes to driving small fasteners such as small-ish sheet metal screws, when I don't want the fastener to turn literally one extra turn when the bottom of the screw head hits the metal, the drill/driver with its adjustable torque ring seems to be the right tool for the job.

 

Apparently up to this point 1/4" hex impact drivers have not had anything like the torque-adjustable ring that drill/drivers do.  However, now there is the so-called 1-Key Milwaukee impact driver and, supposedly, the torque is adjustable. But how adjustable is it? Can this tool drive sheet metal screws without turning the screw one extra turn after the bottom of the head hits the metal?  If the answer is "yes", then that will be my do-it-all tool. 

 

While I'm typing, does Milwaukee intend to instroduce a 12V Fuel impact driver with the 1-key, adjustable-torque feature?  Does any other manufacturer produce an impact driver that has an adjustable torque similar to that of the typical drill/driver?

Thanks.

 

 

[SetBuilder]

IMO skip the one key and buy the Surge impact, it has 4 torque settings.

[Bremon]

Low speed mode on an impact is reasonable. Still more control with a drill/driver. An impact won’t be able to do much more than drive screws and drill the occasional hole. If you’re drilling large holes you’re into impact wrench territory; all you’ll do with an impact driver is wear your anvil, deafen yourself and get the impact housing so hot you’ll burn yourself if you’re trying to get it to drill big holes (I’ve accidentally burned myself driving 6” wood screws lol). 

 

The “one do-it-all” tool you’re describing is likely a good quality drill driver. 2703 when they go on clearance or the new 2803. 

[khariV]

The non OneKey 2753 has a self-tapping screw mode.  I've never used it on sheet metal, so I can't tell you how well it works, but I believe it starts out fast and then slows down after a second or two.  I don't think there's any torque sensor that specifically stops the rotation when the screw bottoms out.

[Bremon]

1 hour ago, khariV said:

I don't think there's any torque sensor that specifically stops the rotation when the screw bottoms out.

If there is it works poorly. Self-tap mode works fairly well but there’s no real accommodating for gauge etc. 

[Darwins Child]

Thanks for the advice, guys.

 

The "Surge" looks tempting, although I understand that as the internals wear and clearances increase only a bit, deterioration in peformance might be rapid.  But maybe that's all "fake news". 

 

Thanks again.

[Biggie]

I'd second a drill driver if you're really worried but we run #10 x3/4" tek screws into 14ga steel with impact drivers all the time and rarely have problems with striping.  I have no experience with one key but the 2753 impact driver has a self tapping mode but I've never been able to get it to work right because it's designed for tapping into like 20-24ga steel.  I have a surge but to be honest I've never tried using the self tapping mode so I couldn't tell you what gauge steel it's optimized for.  I was kind of excited to see that the new impact that's coming out in July is supposed to be optimized for 14-10 ga steel so maybe it'll work better for me.  I personally have found the auto modes on impact drivers and wrenches to be finicky at best but once you learn how to run one they're not that hard to control in just a normal mode.

[Darwins Child]

On 5/29/2018 at 6:39 PM, Biggie said:

I'd second a drill driver if you're really worried but we run #10 x3/4" tek screws into 14ga steel with impact drivers all the time and rarely have problems with striping.  I have no experience with one key but the 2753 impact driver has a self tapping mode but I've never been able to get it to work right because it's designed for tapping into like 20-24ga steel.  I have a surge but to be honest I've never tried using the self tapping mode so I couldn't tell you what gauge steel it's optimized for.  I was kind of excited to see that the new impact that's coming out in July is supposed to be optimized for 14-10 ga steel so maybe it'll work better for me.  I personally have found the auto modes on impact drivers and wrenches to be finicky at best but once you learn how to run one they're not that hard to control in just a normal mode.

Thanks. 

 

The nice thing about the drill/driver is that if you have a lot of small sheet metal screws to drive, such as installing a furnace plenum, when the bottom of the head touches the sheet metal, even though you are still squeezing the trigger, the torque-adjusting collar does not allow the chuck to rotate any further, preventing the screw from stripping the hole. The motor just spins. I understand that with the typical impact, you have to pay close attention to when the head is about to meet the surface of the sheet metal, slow the speed down carefully, and then release the trigger when you see the bottom of the head meet the surface.  All that "paying attention" takes time, whereas, again, with the drill/driver, you know the torque-control is going to eliminate all that "paying close attention" stuff.

 

Thanks again, folks.

[rcarnes911]

DeWalt makes a versa tourqe screwgun for sheet metal I have the drywall version and it works great

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[Darwins Child]

I can imagine a potential design conflict if a torque collar were to be incorporated into the impact driver design. The torque collar would probably have to be "after" the impacting hammers -- that is, closer to the fastener than the rotational hammers that strike rotationally.  If the torque-limiting mechanism were after the hammers, I imagine that the hammering might quickly wear out the torque mechanism.  But maybe not.

 

However, I thought that the torque-limiting mechanism on at least some newer drill/drivers is purely electronic -- either that somehow the motor itself stops when it meets a certain amount of rotational resistance or a slipping clutch is controlled electronically rather than physically.  This, too, probably would not work in an impact driver that does not start hammering until a certain amount of rotational resistance is reached -- one that would already have over-tightened a small sheet metal screw and stripped the hole.

[Darwins Child]

I've done some more imagining and I've decided that what I said previously was wrong.

 

A torque collar should be installed BEFORE the hammering mechanism (closer to the grip) on an impact driver. 

 

Here's why.

 

When the torque is adjusted very low in such a design, for driving say sheet metal screws, the rotational force required to screw in the small screw would/should probably never reach the rotational resistance at which the impact mechanism of the driver would "kick in". 

 

I've never operated an impact driver, but I have seen several videos of them being used to drive fasteners of all sizes.  When smaller sized fasteners are being driven, say in wood, at first the screw is driven in with absolutely no hammering being heard.  As the screw gets driven in further, suddenly a rotational resistance force is reached which initiates the hammering mechanism, which then continues until the screw is fully inserted.  Again, this resistance force would never be reached with a torque-adjustable collar before the hammer mechanism. The screw would already be seated, and the motor free-spinning, long before hammering is necessary.

 

Yes, now I think that a torque collar could indeed be easily incorporated into an impact driver, and there would be my do-it-all tool.  Now a manufacturer should build it! Of course this would be a far-less expensive alternative than those combo kits, so I'm not holding my breath for that new design. 😊