® Screws (Revised)

I am amazed that something every beginning mechanic knows is lost on those who consider themselves smarter. Some people "diss" the Phillips screws found on Hondas, calling them ridiculous and proposing socket head ("Allen") screws as superior; that the heads of Phillips screws by design tend to tear up in use. All I can say is these folks have never learned the correct technique for working with Phillips screws. And at the same time they seem unaware of the potential damage to engine parts inherent in the use of Allen screws.

1. Part of the beauty of vintage Honda engines is their original Phillips screws. They came that way, they look correct that way, they are beautiful. Allen screws by contrast to me look foreign, like an unecessary and inappropriate modification.

2. The Phillips screws in vintage Honda clutch covers and cam covers are meant to be installed and removed using very light-duty cordless impacts. In reality, special t-handled screwdrivers were specified by Honda, but today this parses out to the nutrunner, i.e. low-powered impact.

3. The most common mistake people make in regard to vintage Honda case screws is they choose the wrong screwdriver. Wrong because its size is inappropriate, wrong because its quality is poor, and wrong because a hand-held screwdriver is the incorrect tool for these screws.

4. Among all the other misinformation found online, some folks are very vocal in insisting that JIS Phillips screwdrivers are mandatory for use on Honda's Phillips screws. This is not completely correct because it overlooks the fact that every career Honda mechanic has known for generations: proper-fitting screwdrivers were available and were used by Honda dealer techs long before JIS became known. Honda never characterized their factory tools as JIS. Snap-On never did so either. Nor did SK, Proto, Mac or any of the others who sold (and in most cases still sell) proper fitting and high quality Phillips screwdrivers. The inevitable conclusion is that it isn't only the JIS spec that works best on Honda Phillips screws. Any high quality Phillips screwdriver is equal, whether called JIS or not.

5. Something else career Honda techs know that others seem not to is that Honda case screws that have been undisturbed for a long time should be "shocked" before removal. This simply means hitting them square on their heads with a straight punch and a hamner. A couple smart hits and you'll be surprised at how readily the screw comes out afterward using your impact.

6. Speaking of impacts, one of the most harmful pieces of advice found online is that of the use of hand impacts. It might seem that given the item above a hand impact would double as shocker and impact at the same time. Unfortunately, while at some level this is true, in practice and in the hands of inexperienced users, the hand impact is a deadly piece of equipment in almost every conceivable application. The ditrius of hand impact use can be found all over ebay: broken engine covers, broken carburetors, and screws that after unsuccessful attempts at removal now have to be machined out.

7. Allen screws are a liability in most instances. Normal Phillips screw tightening results in about a 15 inch-pound force. Inch-pounds, note, not foot-pounds. The average person tightens an Allen screw to 50 inch-pounds. Do you think this is of no consequence? The fact is, it is almost impossible to not over-tighten Allen screws in Honda engine covers. If you must use Allens, then use an Allen screwdriver, not a hex ("Allen") wrench or t-handle. At least this will approximate the treatment the original Phillips screws would get.

You're hearing the voice of reason and experience here. Don't discount it.

Original 2018 article

Last updated February 2023
Email me
© 1996-2023 Mike Nixon