JIS Screwdrivers

[Joe Nardy]

As some people know (but many do not) Japan has its own industrial standards, named Japanese Industrial Standards (JIS). This is similar to the International Organization for Standards (ISO) used in other countries, like the US. Anyway, the 'Phillips' head screws found on Japanese motorcycles like ours actually have JIS standard heads rather than Phillips heads. The heads are significantly different. From some online research:

The Phillips system was invented for use in assembling aluminum aircraft, with the object of preventing assemblers from tightening screws so tightly that the aluminum threads strip. The driver will cam out before that happens.

JIS - Often improperly referred to as Japanese Phillips. Commonly found in Japanese equipment. JIS looks much like a Phillips screw (and even more similar to Frearson), but is designed not to cam out and will, therefore, be damaged by a Phillips screwdriver if it is too tight.

Since most people use Phillips screwdrivers on their JIS screws this method tends to strip the JIS heads, causing much aggravation and giving the screws a worse than necessary name. While replacing the screws with socket head screws is a better solution we sometimes have a need to remove JIS head fasteners. Also, some restorers prefer original fasteners. I have been looking locally for JIS screwdrivers for some time and have been unable to find any. I searched online today and found a couple sources:

Ames Supply

ikaswebshop

I ordered the five piece set from ikaswebshop. I will post a review when I receive the tools and test them out.

Thanks,
Joe

[Nessism]

I bought some Vessel JIS screwdrivers and the quality is excellent... http://www.rjrcooltools.com/vessel.cfm I've carefully checked the fit of these into the various GS screws and it's nice and tight, but to be honest a high quality regular #2/3 screwdriver bit is perfectly adequate as well. I believe the key is a high quality tool, not necessarily the JIS tip, but it you don't have a box full of Snap-ons's, you might want to order some of these up.

[Joe Nardy]

While quality tools do make a difference there is no substitute for using the right tool. The important factor in fastener removal is tool to fastener head contact. There are differences between the shape of Phillips and JIS heads:



The radius of the corners is significantly different between the two standards. Phillips heads, and thus Phillips tools, have more rounded corners. This prevents optimal tool to head contact when using the a Phillips tool on a JIS head. It's like using an Allen hex wrench on a Torx head fastener. It might do the job but it certainly isn't optimal. Also, Phillips heads, and thus Phillips tools, are designed to 'cam out' of the head to prevent thread stripping. Obviously, this isn't what you want when attempting to loosen a fastener that was tightened 30 years ago using the correct tool.

Use Phillips tools on JIS fasteners if you like, Krusty approves:



Thanks,
Joe

[TooManyToys]

Easy source:

http://www.mcmaster.com/#jis-%28japanese-industrial-standard%29-screwdrivers/=bl5amb

[TheCafeKid]

Rose had ordered me a set of JIS drivers a couple years ago for my birthday (isn't she the best?? ) but where ever she got them from only had the two biggest (4 & 5?) available so that's what they sent and refunded the difference. She wasn't able to find another source at the time with the smaller ones.

BTW, they DO work better. Feels much more firm and confident in the screw head.

[haggisbasher]

I should have read this last night. I had to resort to the impact driver to get my carbs seperated.

Tom

[azr]

Thanks for the links. Would be a great addition to the GS tool box. Anyone have a good source for the double ended wrenches to make up a bike tool kit?

[salty_monk]

Looks like you made a decent choice Joe....

http://www.advrider.com/forums/showthread.php?t=474338

A friend of mine makes screwdriver bits for Snap-on. He doesn't make JIS's but he did have an odd one of high quality that fits nicely into a 1/4" socket & then I drive it with a standard ratchet. Really helps with a lot of the screws on the GS, the fact that I can put a ratchet, extension etc on it is nice as well.