What is a JIS Screwdriver?
Article by Mark Trotta
Many people think that all cross-head fasteners are Phillips head, but there are two distinctive styles.
What Are JIS Screws?
Similar to a Phillips head screw, JIS fasteners have a "+" shaped recess on the head, but require a JIS screwdriver to remove and install them properly.
JIS stands for "Japanese Industrial Standard", which are fasteners found on Japanese products and vehicles.
In addition to cars and motorcycles, they can be found on snowmobiles, ATV, UTV, 3-Wheelers, PWC'S and other products made in Japan.
Occasionally, I'll do repair work on a classic Japanese motorcycle, such as this 1977 Kawasaki KZ650. And when I do, my set of JIS screwdrivers come out.
Phillips vs JIS Screwdriver
Look closely at the tip on the right. Notice how the end is flat, not pointy, like my well-worn Phillips on the left.
Both of them will fit a cross-head screw, but only one of them will fit right.
I've heard techs complaining about cross-head fasteners rounding off, or saying that the material is too soft. In reality, they're probably trying to remove a JIS fastener with a Phillips head screwdriver.
How Can I Tell a JIS Screw?
Most, but not all JIS screws have a dot stamped in them.
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It's quite common to find stripped bolt heads on old Japanese cars and motorcycles.
Looks like a Phillips screwdriver was previously used on these ignition points.
Here's another example:
On a typical Mikuni four-carb rack, there are eight carburetor holder screws.
The torque spec is not always given in the factory service manual, but they are on there tight!
The first time you use a JIS screwdriver, you'll realize the difference.
They fit snug and secure, allowing easy removal and correct torquing.
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Because JIS fasteners are made in many sizes, you'll want to have several different-sized screwdrivers. Here's an inexpensive set from Hozan:
Shop: JIS Screwdriver Set
This set offered by Riftwild has magnetic tips and full tangs with solid shafts:
Shop: JIS Full Tang Screwdriver Set
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