Tinkerdwagon 101: Fixing a Borked Philips Screw Head![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1070568;image)
Sometimes you'll find yourself needing to use a Philips screw you have on hand (either it's a special screw, or one that's not commonly available to buy, or you're stuck onsite with a rack full of switches and 2 screws short... you know the story), and just don't have a choice about replacing one with a buggered-up head.
This morning I'm doing some house-mending, and I need to install some wall anchors. I have just enough for the project, including one with a chewed-up head from several off-on cycles of trial-fitting. If a screw is soft enough to chew up easily, odds are it's also soft enough to repair using the following technique.
![Blah :blah:](https://www.eevblog.com/forum/Smileys/default/blah.gif.pagespeed.ce.iJS9qlFEPg.gif)
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1070572;image)
First you need a work surface suitable for hammering on; a vise is preferable, but in a pinch you can use a 10" or 12" adjustable wrench like the one I have here, provided you have a smallish hammer with approx the same or slightly less mass. I keep one of each in my site bag for this and a thousand other reasons.
![Wink ;)](https://www.eevblog.com/forum/Smileys/default/xwink.gif.pagespeed.ic.cldandycH0.png)
Put the screw between the jaws like so and tighten it up just finger-tight; you aren't trying to grip the screw, just supporting the shoulders of the head snugly and evenly so they don't get destroyed by your hammering.
Remember to wear eye protection whenever hammering on things; eye-patches are ONLY kewl on people in the movies. ![Tongue :P](https://www.eevblog.com/forum/Smileys/default/xtongue.gif.pagespeed.ic.J5mTe0A2NA.png)
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1070576;image)
What we're trying to do here is to peen the metal of the screw head such that some the lost metal is replaced with that metal deformed by the peening process. For this, you need to place the hammer so that the face is flat and square against the head of the screw, and used moderate, controlled strikes to land your blows flat and square.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1070580;image)
Typically, only a few blows is required; once you do this a few times, you'll notice that the sound of the impact changes when you have achieved a good peen. You want a nice, flat peen like this across approx half the head of the screw or so. If you use a hammer with a smooth face that hasn't been all chewed up like mine, the peen will also be nice & smooth; barely discernible from a new screw.
![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/xfacepalm.gif.pagespeed.ic.EBDwh1hCfo.png)
I've noticed that these combination head screws seem to be the worst offenders; they seem to be MADE to strip out easily.
![Rant :rant:](https://www.eevblog.com/forum/Smileys/default/rant.gif)
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1070584;image)
Next comes the dangerous part: Reforming the Philips slot. We're going to use an appropriately-sized (P1/P2/P3, etc) drill/driver bit as a die to reform the slot. Place the bit in the slot so it is as close to the original orientation of the slot as possible; it will know where to go.
Remember to apply eye protection whenever hammering on things; wearing a eye-patch is only fun as foreplay. ![Evil >:D](https://www.eevblog.com/forum/Smileys/default/xevil.gif.pagespeed.ic.tdrs7Uj5gu.png)
Choose one that is new or nearly new to get the best, cleanest impression, and try to use a name-brand one if you have it. The cheap Chinesium ones tend to be brittle and shatter when struck; not a fun time if you're holding it between fingers ( I recommend pliers if using the short ones); the longer impact bits are safer, but the shorter ones seem to make a better impression. It's your fingers, your blood, & your pain, so it's your choice.
![Lips Sealed :-X](https://www.eevblog.com/forum/Smileys/default/xlipsrsealed.gif.pagespeed.ic.8oTr2_WWv_.png)
Just a couple whacks and you'll hear the impact change to a dull thud; this means you're bottomed out and any more whacks will just waller-out the slot.
STOP HAMMERING!![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1070588;image)
The money shot: This one turned out ugly because my hammer face was ugly. But the Philips slot is good and the bit gets a good bite again. Now to go hang some mirrors.
![ThumbsUp :-+](https://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif.pagespeed.ce._JElyJQqdB.gif)
mnem
*passing it on to the next generation*