After a few years of working on Japanese vehicles, I finally realized the Phillips head screws that I've been sometimes stripping are not really Phillips head screws at all. It turns out that Japanese equipment uses screws that are built to the Japanese Industrial Standard (JIS) B 1012 specification.

These screws look like a Phillips screw, but are designed not to cam out and will therefore be damaged by a Phillips screwdriver under high torque. JIS screw heads are usually identifiable by a single dot or an "X" to one side of the cross slot.

This thread provides information about the difference between JIS and Phillips screws with examples of recent JIS driver purchases.

Let's start by watching a video that describes the difference between a JIS and Phillips driver.


Here's a picture of the JIS drivers I ordered from Japanese sellers on Amazon.com.

The Vessel ratcheting driver set turned out to be the most useful because it contains 1/4 bits that I can use with my existing offset driver set. The Vessel #2 and Hozan drivers are great for regular use. In this thread I will show how I recently used the Vessel set to remove fuel injector screws and a screw on the ECU box.



The ECUs on my Maximas use JIS screws on the case and with the mounting bracket. You can see the screw in the ECU picture below contains the JIS mark.



In this picture I use the Vessel #2 JIS driver to remove some old corroded Nissan injector cap screws.

You can see how the driver and screw match so perfectly that the driver stands up in the screw without being held into position.




Here's a picture of Vessel JIS ratcheting driver set that I ordered from Amazon.com. I see where the product was made in Osaka Japan.

Does anyone know how to translate the Japanese instructions?



Here's a picture of the Vessel ratcheting JIS driver in action on a 4th gen injector cap screw. The vehicle in the picture is junk yard car that used for testing the Vessel driver.



Using a JIS driver made short work of removing the injector cap screws on this 4th gen.



Conclusion:

If you plan to work on Japanese vehicles, you will benefit from having a JIS driver set in your toolbox.

Having the right tool to do the job will save time and avoid problems associated with using a Phillips driver on Japanese Industrial Standard (JIS) screws.

 

I had learned that American phillips and Japanese "phillips" were different a long time ago. What I learned to do was grind the tip of the phillips screwdriver off a little bit and it fit a lot better. It still isn't perfect. The vanes on the American screwdriver have more slope than the Japanese screw. Super tight screws like the fpr still need the Japanese driver, but it works quite well for the others. And the screwdriver still works just fine on an American screw.

 

I'm still learning, even though I'm getting older!

Thanks to guys like you! Glad you guys are here!

I will have to get setup when I do the injector project! I'm glad I'm not going in blind sided and with a higher chance of failing now!

 

Yeah...work on any Mikuni carburetor and you'll definitely see the value of the JIS screwdrivers!
They are much more expensive, but worth it.

 

That explains why the Phillip heads on my Japanese vehicle were so easily stripped.....Never knew this...Thanks guys!

 

Nice find, I'm torn between the ratcheting handle set you got and this set here:

 

I like the handle grip better. The only thing that might be a difference is the 1/4 inch bits can be used with a small offset ratchet driver in a tight place removing the ECU screws. But that would be one of the few places where a short bit comes in handy.