# Bit slips inside chuck when drilling, what am I doing wrong?



## Bud Cline

Not familiar with that particular tool - what type of chuck does it have?
Is it SDS?


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## Mr Chips

It's pretty normal on these keyless chucks, especially if you are really pushing on the drill. If it was an old school Jabobs chuck with a key (or an SDS) you wouldn't have this issue.

I have two suggestions that should help:
1: look for drill bits that are manufacured with "flats" on the shank end. This will help a lot
2: If you find yourself really bearing down on the drill, DON'T! when you push down in rotohammer mode you really make the tool less effective. Let the machine do the work, you should just be holding it straight

EDIT: a third suggestion is to pull the bit up out of the hole a little more often. this will help with dust removal, which will keep the bit from binding ( and ultimately slipping). The water may actually be making it worse, as it may be causing the dust to cake up in the flutes of the bit, making it harder for the bit to get the dust out of the hole


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## Mr Chips

Bud Cline said:


> Not familiar with that particular tool - what type of chuck does it have?
> Is it SDS?


from his description I'm willing to bet its a standard keyless chuck, not SDS


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## Tom Struble

and the dewalt keyless chucks are known to be a problem


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## hvaclover

The chuck won't tighten well on some of the older De Walt stuff. I had to use two adjustable pliers to tighten my De Walt hammer drill so the masonry bits would not slip. 
When I switch to my newer Milwaukee hammer drill I have no problem.
The chucks are better than the ones the De Walt uses.


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## Red Squirrel

It's a key chuck, but the end of the bit and the way it goes in, is basically the same as keyless. There's not much as far as something for it to really grab on to and hold the bit steady.


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## del schisler

Red Squirrel said:


> It's a key chuck, but the end of the bit and the way it goes in, is basically the same as keyless. There's not much as far as something for it to really grab on to and hold the bit steady.


If it were me i would take and grind it flat on both sides. And when you put in in the chuck put the pointed part's of the bit in the open parts of the chuck and tighten. I bet it won't slip now. I do that to some drill bit's i use in my dewalt keyless chuck.


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## Red Squirrel

hmm not a bad idea, I'll have to try this.


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