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I recently bought a $35 cordless screwdriver that came in a suitcase with screwdriver bits. I was in shock when the Pozidriv bit splintered after screwing only 3 1-inch screws in the leg of an unvarnished wooden ladder. After the initial shock, I used the other Pozidriv sizes but not surprisingly, they all splintered after screwing a few screws. Now all the Pozidriv bits are dulled out and completely unusable.

Can anybody tell me what these screw bits are made out of so I will not make the same mistake twice ?

Any suggestions about which metal bits to buy? Do titanium-coated bits wear out soon? How soon? What about chromium-radium bits?

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All bits are a steel alloy base. The proper alloy and heat treatment is what makes the difference. Too hard, and the brittle bit splinters like you have experienced. Too soft, and the bit wears quickly. The manufacturers of contractor grade tools have figured out the ideal compromise for maximum durability. –  bcworkz Nov 25 '12 at 19:43
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For $35, you can't expect all that much. –  Steven Nov 26 '12 at 3:29

4 Answers 4

I think the bits as basically very low quality. When you go to your favorite store, simply buy one of the contractor grade of bits like DeWalt, Kolbalt, Irwin, Vermont American etc. Be careful what kind of jobs you tackle with your light duty screwdriver. I'm sure it does not have the power to drive longer screws into hard woods like decking etc. You have to hold a lot of force against the screw in these situations or the bit will slip, spin and dull, as well as strip out the screw head.

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Here is a great set of DeWalt bits and quick change extensions: amazon.com/DEWALT-DW2176-37-Piece-Screwdriving-Set/dp/… –  shirlock homes Nov 25 '12 at 13:21
    
Still can't figure out how to reduce a long link to a text phrase. :( –  shirlock homes Nov 25 '12 at 13:22
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Use [text](link) –  ChrisF Nov 25 '12 at 13:48

As @shirlock homes has stated it sounds like a low quality bit. I am unsure of the durability of the coated bits you mentioned as it is often a marketing ploy. Some manufacturers coat a low quality bit in an exotic sounding material. What you get is a cheap bit with a very thin layer coating it. If you haven't noticed the major "Pro" lines don't make these coated bits. I have also had issues with multi-drive screws. They have a combination head, square/phillips/pozidrive. The drivers all seem to fit poorly and round the bit or the head. I would reccomend buying quality drivers as you need them or a quality set of mixed drivers. The quality set may cost half of what you paid for your screwdriver, but it should last for years.

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Think of it this way; is it easier to replace a broken bit or remove a screw with a stripped out head? It is always easier to replace the bit. It sounds like you may need to work on your technique a little. Bits shatter like you are describing from the shock received from coming to a quick stop at the end of its travel. It is best to ease the screw in the last bit by slowing the drill and applying extra force at the back of the drill. Do not run the screw in as fast as you can and smack the bit when the screw reaches full depth. You want to control the depth the head penetrates as well by slowing and pushing as you reach full depth. Another mistake noobies make is to run the bit in the screw without turning the screw. This is pointless and does damage the bit and screw. Do not do it. If the screw does not turn do not "rattle" the bit in the screw head. Sometimes people think they can hammer the screw home this way and it does not work. If a screw gets stuck without being fully driven back it out part way and while pushing firmly at the back of the drill slowly increase trigger speed until the screw turns and goes in all the way. If a screw will not go in after that then you probably need to drill a pilot hole slightly smaller than the diameter of the threaded portion of the screw. This brings up a possibility for you; are you using a variable speed drill? A single speed drill will be very difficult to drive screws with and could result in broken bits since you can not adjust the speed to fit the situation. Finally, if you are depending on speed to drive the screw you are not in control of the situation. The important thing is to push hard at the back of the drill and use the speed that is appropriate. If you are on a ladder or drilling above your head you may need to reposition to get enough force directly in line with the screw travel.

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You might need to make sure that you were not using Pozidriv bits on standard Phillips screws. For hand-used tools, coating won't help much if the bits themselves have low quality. Basically it's all about torque and HRC.

For example, if the bits are made of #45 steel, even after heat treatment, its HRC is still low and can be easily worn. A case like yours might use far worse material.

But if it's made of S2 steel and processed with heat treatment, the HRC can reach 60+. Bits like that can break apart quenched screws.

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Welcome to the site; I removed the self-promotion bit (see the help center for more information). You're welcome to put links to your product in your profile (either the website or the about me fields). –  Niall C. Mar 14 at 13:50

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