Have you ever been knuckles deep in your Subaru or Mazda, fiddling with some frustrating screw, only to feel it strip beneath your screwdriver? It may not be the fault of your technique, which I’m sure is excellent, but the fault of your tools — that’s right, you may not be a poor craftsperson this time. If you’re struggling with Phillips screws that just seem to slip and strip, you may instead be working with JIS.
JIS screws are the Japanese Industrial Standard, a very similar-looking cross-shaped screw head. JIS screwdrivers even work perfectly well in Phillips screw heads, and the reverse mostly fits — until you try to apply any torque, at which point the Phillips driver will strip its way out of the JIS screw. That’s not the fault of poor technique, but a fault of the Phillips screwdriver’s design. It’s shaped in such a way as to cam out at high torque, but that shape makes it an imperfect fit in JIS crosses.
A simple solution
Technically, the JIS standard has been largely overshadowed by updates to the international ISO Phillips head shape, which is meant to more closely align the two to a sort of middle ground. But the updated Phillips, while an improvement, still isn’t perfect for older JIS screws. Luckily, despite being a somewhat dated standard, you can still pick up JIS drivers — even from reputable outlets like McMaster-Carr.
Personally, once I finish my move and get my new shop all set up, I’m likely to swap my Phillips drivers for JIS hardware. There’s no real detriment to using the Japanese design, other than the cost of replacing your existing drivers. I won’t go so far as to start filing down my multitools, but there’s never anything wrong with having a more positive grip from your screwdrivers — so long as you remember not to over-torque your bolts. That, though, really is an issue with your technique. I can’t solve that one for you.
