Classic Motorcycle Build

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 is a JSS screwdriver

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.

Kawasaki KZ650 project bike

When repairing/maintaining my 1977 Kawasaki KZ650, I use JIS screwdrivers.

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.

what is a JSS screwdriver

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.

how to tell a JIS screw

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It's quite common to find stripped bolt heads on old Japanese cars and motorcycles.

what is Japanese Industrial Standard

Looks like a Phillips screwdriver was previously used on these ignition points.

JIS screwdrivers for Japanese motorcycle repair

Here's another example:

On a typical Mikuni four-carb rack, there are eight carburetor holder screws.

A set of JIS cross-head screwdrivers is what you need for vintage machines with hard-to-remove fasteners

The torque spec is not always given in the factory service manual, but they are on there tight!

JIS screwdrivers for vintage and classic Japanese vehicle repairs

The first time you use a JIS screwdriver, you'll realize the difference.

Japanese Industrial Standard Screwdrivers and Bits

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:

what is a JSS screwdriver

Shop: JIS Screwdriver Set

This set offered by Riftwild has magnetic tips and full tangs with solid shafts:

Japanese Industrial Standard screwdrivers

Shop: JIS Full Tang Screwdriver Set

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