impact screwdriver

[Nonny]

Harbor Freight sells one of those "tools you put in your toolbox and only get out rarely when all else has failed." It's called an impact screwdriver. They've been around forever, and the one I just got cost less than what I paid for one 55 years ago.

What they are is a very heavy solid steel handle with a coarse pitched screw thread inside, so to speak. Inside the threaded area is a mated shaft with reversing toggle, and on the end of the shaft is a hex holder for various screwdriver bits. The tool is a heavy duty version of the Yankee drill we all remember. They have a socket wrench-type of shaft and apparently can also be used on bolts, but I've never tried that, since I have a pneumatic wrench that works well. Their best application is in loosening frozen screws, where an inward application of force and twisting motion is needed.

To use the impact screwdriver, you place the appropriate bit in the holder and hold the screwdriver firmly while tapping on it with a hammer. The impact forces the bit into the screw, helping to prevent the head from stripping, while the coarse threads make the bit twist just a tad. Usually, that's enough to break loose a frozen screw if you're lucky, and you then follow up with a regular screwdriver to finish the job.

The first one I had I bought as a teen to work on my motorcycle's engine and had it for around 40 years. During that 40 years, I probably had to use it a dozen times at the most. However, each and every time it saved the day for me. The one Harbor Freight sells appears to be a clone of my old one and I suspect it'll serve the purpose longer than I'll ever need.

Nonny

[David Nebenzahl]

On 7/12/2010 12:24 PM Nonny spake thus:

I agree with you that this is a great tool. No batteries or power required, either. Every toolbox should have one.

[willshak]

Nonny wrote the following:

Yes. Put it next to the nut breaker. The tool to crack a nut that won't twist off a bolt.

[Nonny]

No argument there. That's yet another one of those tools for when all else fails.

Nonny

[Steve B]

Best $10 you'll ever spend. If you know a tool guy, one of these is a great stocking stuffer. Like you said, you only need it about once every 1.5 years, but when you do, nothing else will work. If you keep it in the nice little metal box it comes in, it always looks like new. It does take a while to learn how to use it, though. And that is to use it FIRST, before you strip the head off that bolt. One or two smacks, and you're done. Same for setting a bolt. A couple of smacks, and it's there.

Steve

visit my blog at

watch for the book

[David Nebenzahl]

On 7/12/2010 3:21 PM Steve B spake thus:

Also, it should be pointed out that the tool should be set to twist in the correct direction before applying it, so you don't tighten the screw or bolt instead of loosening it. (Sounds stupid, but don't ask me how I know this ...)

[Oren]

Okay, I won't ask. But I know you live in Berkeley.

[Bob F]

And one of the tricks is not to twist it all the way before you hit it for tight screws. That way it applies more force down into the head for the rotational force it generates, which reduces risk of stripping out the screw head.

[rlz]

Here's the link that I found

Robin

[Bob F]

That thing has a finger guard on the grip! What kind of wimp would want that?

[notbob]

These were a requirement for a motorcycle mechanic, as ALL Japanese motorcycles used phillips oval head screws everywhere. If they were the least bit tight or stuck, you'd strip out the phillips slot. The only alternative was an air impact wrench, a 3/8" drive butterfly model the hands down favorite.

I'd be very leary of a HF driver. It's been my experience that Korean made drivers are the best, the Japanese made drivers the worst. It's not the driver at issue here, but the bits. Japanese phillips bits are like those crappy bits they sell by the gross and lumber yards for cordless drill guns. They wear out or twist. My Korean phillips bit looks brand new, 45 yrs later, and I've assembled and disassembled too many motorcycles to count. Somehow, I don't see Chinese steel hanging in there for the long haul. Hold out for a Korean driver if you're going to be doing phillips head screws.

BTW, a 2 lb sledge is perfect for driving:

nb

[ransley]

Its now one of the best ways to drive wood screws, there are many 18v models avalaible at any box store

[Bob F]

Not even in the ballpark.

Ever read before you post?

[David Nebenzahl]

On 7/12/2010 5:44 PM Bob F spake thus:

Ransley? Nah. Too much trouble.

[Steve B]

Well, hell, not me, for one. I used to have a finger there, but there was this incident with an impact driver and ..............

Steve

visit my blog at

watch for the book

[Steve B]

Its now one of the best ways to drive wood screws, there are many 18v models avalaible at any box store

reply: There's an 18v. manual impact driver? I want one!

Steve

[ransley]

I dont know what the difference is between Manual Impact and one of the new 18v impact drivers is, but they are labeled as an Impact Driver, Some are not big but all major cordless tool makers offer them and they are cheaper than many drills. I saw at sears several big and very heavy 24v inpact drivers by maybe Sears and Dewalt that looked like they could do any job on a car, and there are many more lighter duty units, lighter than drills for screws. For screws they surpass drills in heavy work like making decks. Popular Mechanics magazine just did a review of 9 LiIon Impact Drivers, but not the big ones I saw at Sears.

[LSMFT]

Put a screwdriver bit in your impact drill. Same thing.

[JohnnyD]

Having used both, I can tell you that you are very wrong.

Your impact drill doesn't impact nearly as hard as the hand tool. That makes a HUGE difference on a stuck screw. In the case of the previously mentioned motorcycle engines, with steel screws in aluminum cases, an impact drill would strip the heads, or break the heads off without loosening them. The hand tool applies a lot more force per hammer blow. It never strips the slot, and if it snaps the head off, it usually also turned it at least a little, so you are left with something to work on.

That first movement of the screw, even if slight is the key. At that point, you can predict who will win most of the time.

[Tony]

I agree with most of this thread except the above "hold the screwdriver firmly while tapping on it with a hammer".

Tapping it? I hit it with a 2# sledge like notbob mentioned.