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I'm trying to drill some 5-10mm holes in 1-1.5mm thick steel. I'm using a DeWalt DCD777 18V cordless drill with Bosch HSS bits (which claim they're made for drilling into metal). Both the drill and the bits are brand new.

No matter what I do, the bit almost always binds into the metal just as it's about to exit the piece I'm drilling, starts twisting inside the chuck, and gets damaged.

Here's a photo of the damaged bits. You can see, especially on the bottom of the bigger one, how the inside of the chuck rips into the bits.

Now, my question is not about how to stop the bits from binding, I've found plenty of advice about that. My question is, is it normal for the bits to slip like this once they do bind? I've been told that a keyless chuck is not as secure as a keyed chuck, which of course makes sense, but how can I tell if it's normal behavior or a faulty chuck? As I said, the drill is brand new, I can still return it and get a refund (or another drill), but I'd prefer to do this only if the machine is actually faulty.

I am pretty sure I tightened the chuck as much as it's possible to do by hand. I'm a pretty strong guy, and the method I use is: one hand on tool, the other on the chuck sleeve; tighten as hard as I can, until I can no longer get it to ratchet. I've also seen videos like this, which advise to back up the chuck a bit after tightening it, to engage the spindle lock, and I tried that too.

The bits do not slip at all when drilling into wood, even on holes as deep as the bit is long. Even when drilling steel, they only slip when the bit actually binds.

So, any tips on how to tell if a chuck is weak?

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  • They don't slip with mine - and I use a mixture of cheap and more expensive bits. Usually when the bit "locks" in the work then the slipping torque clutch operate on the drill instead of the bit spinning in the chuck. – Solar Mike Jan 16 at 9:03
  • Also, I find no difference between keyless and keyed chucks for bit holding but there is a difference in speed of use. – Solar Mike Jan 16 at 9:04
  • I'm using the drill setting on the tool, which I believe disables the clutch. It won't skip, no matter how strong it binds, so something has to give, either the piece I'm drilling (clamped too securely to the worktable), the bit (stuck fast in the metal), the chuck, or my hand, right? – Victor Stanciu Jan 16 at 9:13
  • @VictorStanciu- most new drills have 2 or more drill settings. DeWalt drills have a dedicated drill setting (this is the collar just below the chuck) and a 1-10 (?) clutch dial that allows the clutch to slip depending on the torque. – ojait Jan 16 at 16:59
  • @ojait on my model they're unfortunately on the same collar. You can't select the drill setting and the torque: i.imgur.com/skJqabO.jpg. Only the speed can be chosen independently. – Victor Stanciu Jan 16 at 17:07
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Yes. It's a common occurrence especially when I use a DeWalt keyless chuck. If the chuck is sized for 1/2 inch capacity it will happen more than 3/8 or 1/4 inch chucks (from my observations).

If I really need a driver or a bit to remain secure and the chuck to keep a solid bite I'll tighten the chuck with Channel Lock pliers or something similar. Grip the chuck with pliers and slowly press the switch until the drill is almost ready to leave your hand.

To facilitate the bit not binding just before it completes the boring task; apply lubricant just after you start the opening. It also helps to keep the bit at a 90 degree orientation (if applicable). Also drilling with the RPM's on 2 setting (fast), but intermittently pressing the trigger (goosing) will make it easier on the bit and the drill with less binding.

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  • I can’t believe that you need pliers... I find I can grip the chuck by hand and overide the motor whichever gear it is in. – Solar Mike Jan 16 at 17:18
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    @ojait Thanks a lot for your answer, it set my mind at ease about the drill. I've meanwhile ordered a high quality step bit (as tested by Project Farm) to help with these particular holes, and I'll definitely try the technique you describe too. Thanks again! – Victor Stanciu Jan 16 at 18:38
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    No chuck will hold a round bit from slipping if it jams at high power. What you can do is grind flats on bit end in chuck. When almost at end should let up on pressure and go slow. Cause is breaking though steel only a little bit, the rest of hole is still there and catches the bit below the tip. – crip659 Jan 16 at 22:19

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