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OT: When is a Phillips screw not a Phillips screw?

5K views 31 replies 19 participants last post by  Fonzi 
#1 ·
When it's a Japanese Industrial Standard crosshead screw.

For 20 years I've been routinely stripping the heads of "Phillips" screws on my Kawasaki and I've probably done a few on the Subaru too, being ignorant of the difference. Particularly annoying when trying to remove carb float bowls which have screws buried deep in the guts of a motorcycle.

Finger Metal


While this is not a Benz issue, I imagine some of you also have Japanese stuff to which this is pertinent. The problem occurs because of the amount of torque that gets applied to some rather small surface areas. If you've got a tool kit that came with your Japanese bike or car, the screwdriver in it will be a JIS screwdriver. You can use a JIS tool on a Phillips but you can't do vice versa without possibly stripping the screw.

I couldn't find any when I was last at Hazard Fraught Tools, so it doesn't look like the Chinese use them, but I'm only assuming. But you can make one out of a Phillips head one, courtesy of some Wing Nuts:

https://goldwingdocs.com/forum/viewtopic.php?f=16&t=15547
 
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#2 ·
Since I've never been called a professional "tool man", I regularly use the wrong tool for the job and have run into the differences you point out between Phillips and JIS heads. I could never understand why some of the drill screw heads in my toolbox sets fit while others didn't fit very well, if at all! The problem is I was never aware that there was a difference! Unfortunately, I'll still never be a professional "tool man", but thanks for the heads-up.
 
#5 ·
I have a Subaru automobile and a Suzuki motorcycle.

I own a set of JIS screwdrivers.

I use regular Philips screwdrivers on the Subaru.

I use JIS screwdrivers on the Suzuki.

Not all Japanese vehicles are fitted with JIS screws. I also have Honda, Mazda, and Toyota cars and I’ve owned Nissan in the past. All Philips. However the bikes get JIS.

Luckily Japanese bikes run really well and repairs are minimal. I wonder WTH the guys who own Hesketh motorcycles used — imperial or metric or what? Heh.
 
#12 ·
Have you dealt with the all aluminum JIS screws on a Honda motorbike? Once you get them off you never want to screw them back in... it was routine to replace every JIS screw with allen head metrics. I still have a stockpile of these things.

Why anyone would design an engine with aluminum screws is beyond comprehension.
 
#19 ·
JIS / Phillips Screws

I was a Honda Motocycle Mechanic early in the 1970's and quickly learned that when faced with a 1956 ~ 1975 #2 looking philips screw on a Honda side cover, use a standard #3 Philips and no damage will occur .

Grainger, Inc. stocks a wide selection of good quality JIS screw drivers .

I've bought them off Amazon too .

I still use a hand impact driver 50 years later, they work great but only if :

A. you use the correct bit

B. whatever bit you use fits the screw head firmly ~ if it's all cheesed up from the DPO/DPM, get the proper size bit and a 32 oz. hammer and bang the bit in until it fits properly, then use the hand impact tool .

C. you *SMACK* it ~ if you use a light Chinese hammer or just tap the tool, it cannot work and you'll think it doesn't work when in fact they work very well and never leave tool marks on the original JIS screws *if* you use it correctly .

I was unable to get the door striker screws loose using a hand impact tool, I ever tried smacking the crap out if it with a 3 # single jack, no dice, the electric impact buzzed them loose *instantly* .
 
#21 ·
I posted this on a Suzuki forum some years back:

Most newer Phillips screwdrivers and bits do not follow the Phillips standard closely and in fact are profiled more like the JIS spec, with one notable exception--the tip, which is too pointed tp properly engage a JIS screw head. Usually grinding or filing off a bit (no pun intended) of the tip can make them fit JIS screw quite nicely:



Here is a video (1.0 MB .wmv file) showing the improved fit (same two bits as shown above) in a JIS screw (you may have to save it to view it depending on your browser):

 
#22 ·
Yes, I just took a couple of Phillips head screwdrivers and used my bench grinder to take off a bit of the tip. I took maybe 1mm off the tips. I noticed when putting a Phillips head screwdriver into a JIS screw, you can rock it back and forth more because the tip bottoms out before the side bits get a decent hold on the slots. My Kawasaki toolkit JIS screwdriver will not rock at a larger angle and my modified Phillips head drivers are now similar.

The JIS driver will work pretty well on a screw previously stripped using a Phillips if the screw doesn't need too much torque. Since the Phillips can't reach to the bottom of the slots, there is an unmolested bit of sidewall at the bottom that the Phillips couldn't reach.
 
#25 ·
Why anyone would design an engine with aluminum screws is beyond comprehension.[/QUOTE said:
I’d guess that some engineer at that company figured out that the reduction in shipping weight would save a few yen over the long run. Or he had a brother in the aluminum fastener business. Maybe both.



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#26 ·
having been working on honda bikes for neerly 40 years, and many other brands i can atest to the to the jis engine hardware BS

as a general rule, if i dont know when the last time the philips/whatever screw has been turned i will find the tightest fitting bit and ALWAYS give it a whack with a hammer before attempting to unscrew, it has a habit of A seating the bit and B shocking the threads so it comes out first try....

btw torx bits are GREAT at removing stripped allens..and are also great for removing "euro" wheel locks IE the ones you stick a spline drive into
 
#28 ·
I used to build crates that went to the US of A from Canada.
Robertson (square) bit screws are quite popular here.
US customers started calling and asking "What the fuck are these fucking fuck fuck screws????"
We'd FED-Ex them a couple of Robertson bits to get them going.
We then switched to Phillips screws...I still close crates with Phillips to this day.
 
#30 ·
THANX Fonzi ! .

That was interesting .

Yesterday I finally began working on resurrecting a Brazilian made Honda CB125S Motocycle and I was surprised to see the litle dot on each screw head indicating they're all JIS .

I thought JIS headed screws stopped in the 1970's .
 
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