Let’s look at this in more detail …..
Theoretically, you are staring a JIS screw, and wondering how to approach it. If you have a Phillips head driver, then with extreme caution. Once the initial point of resistance is reached, the Phillips head will skid out, wrecking the head of the JIS screw
So, then you try one of those new fangled (circa ‘70’s) “Posi-drive” jobbies, which introduces another set of catch points on said screw in a star pattern. Now we’re talking, as long as that JIS screw is only a little bit more than hand tight that is. A much better fit, but is it good enough ? – it certainly feels like it
Then you take a Japanese production line, fully automated, where the production tools take the JIS screw to its correct torque in one smooth robotic move. No room for error, the screw has withstand the force of the driver used with zero slip. Sure, it only has to happen “once”, but it has to happen reliably every time, hence the evolution of the JIS standard
The difference between Posi-drive and JIS may seem small, but look at it this way. Attack a JIS screw with a Phillips, and it will skid the head after , say, 50% force. The Posi-drive, perhaps up to 80%, but with the JIS head, suggest 90% (no driver head is perfect after the screw has been sitting there for a decade or so)
And if you need to “whump” it with an impact hammer, you’ll need all the help you can get
With the increased use of power tools, something the Japanese production lines have been doing for years, comes the need for increased “accuracy”. A friend of mine (my old boss), asked me how I managed to screw thing together using a drill without any problems – I replied “Make sure you have a tight fit, make sure you are square on, and just go in slowly and steadily”. Selection and angle is everything – “awareness over confidence” – this is the philosophy behind JIS
I grew up smacking the crap out those screw in the seventies, how I didn’t crack the cases was a miracle, but it was a “right of passage” back then. Ten minutes getting most of the case screws out, then three hours hammering on the remaining one. But times change, and so does the way we approach things
The pre-fix “PZ” denotes Posi-drive, and while that may well suffice, you could do better
JIS Screwdriver Bit Set and Driver 7 Pc For Japanese Industrial Standard Screws | eBay
How you approach this is up to you, but personally, I’d get both the ones Ski has proposed, and the one’s I’ve mentioned above. Between the two, you are likely to find a solution ……..
