JIS screwdrivers

In the article and discussion the driver standing on it's own in the screw is taken as a sign of a proper fit. When pressed to use the tool at hand
I will take a light grind or a swipe or two of the file to flatten the tip of the driver a bit. Not a lot, just a little, often "helps" the fit. Many screwdrivers are just a bit "too pointy"

Agreed - I have found this to be the case with many Phillips drivers - even bits of a reasonable brand.

Haha, thanks Pete. What can I say? I'm a frugal kind of guy.
" A person who never made a mistake never tried anything new." Albert Einstein

You know I've thought of doing exactly that, squaring the edges a little with a file.

Have you ever used (or even seen...) Robertsons?

These are known in the US as "square" but they were actually developed by a Mr. P.L Robertson of Guelph ON who, I think still holds the patent on the design, but licences it to tool making firms. Robertson screws and drivers come in 4 sizes (#0 to #3 I believe) but the screwdrivers are also colour coded (and it is absolutely standard across any brand of driver - see the photos) and that's how everyone refers to them here:
0 = yellow (seldom used)
1 = green (often found in electrical boxes etc).
2 = red (the most common size)
3 = black (not often found except in heavy duty roles like holding the legs on a dining room table or securing the springs on a recliner chair)

The fit between the screw and the driver is amazingly good: you can walk around with a screw loaded on the driver and it won't fall off, and they are very difficult to strip. Nowadays, Robertsons are commonly used in Canada in furniture and electrical cabinets, but they aren't often found outside of the country. A buddy of mine lives in southern Germany in a Canadian made pre-fab house called a Viceroy (I think it must have been brought over there by a member of the Armed Forces in the 1970s). His entire house is put together with Robertson screws and he wanted to do some renovations but couldn't find drivers or replacement screws - so I sent him a set of drivers and a couple of boxes of screws.

Another funny story goes that around 1910, Henry Ford recognised the Robertson screw as far superior to the Phillips design, but he would only use them if old-man Robertson would sell Ford the entire company and the patents, so that he had an exclusive. P.L. wouldn't sell....and so the Robertson screw was doomed to obscurity in the frozen wastes of Canada, plus a few high furniture makers abroad. Much later, somebody invented the Torx(tm) bit and screw for automotive use - bit it is much more expensive to make than the Robertson.

Tools are fun!

Nope, never seen or heard of a Robertson.
And yes they are fun!

MaxPete, Marlette built their mobile homes (or trashy trailers if you prefer) with Robertsons and Craftsman had the dirvers. I've had to argue about the insurance replacement value with agents before because every stick in the home is #1 grade SPF. There is a fair step in price between #1 and #2 lumber.

Interesting.

#2 Square drive; the mobile home and RV industry used them for years. We had a lot of mobile home manufacturers in our area. My business used to buy their surplus, I had boxes and boxes of square drive screws. Cabinet and door hardware for them all came with the square drive screws. Anyone remember dealing with the early Honda JIS engine screws made out of reprocessed dog food cans, you couldn't really tighten them they would just stretch and stretch.

They were made out of the very finest margarine grade steel....

Anyone care to show one of their ground down Phillips? perhaps a side by side.. I have been taking that pointy tip off one of mine, but still managed to booger up a butterfly shaft screw (yes gggGary, I may not have had enough downward pressure). I am a visual learner, so pictures and youtube videos are my friends.

IMNSHO that is not the place to be trial and error regrinding screwdrivers. I also was gifted a set of Vassel JIS drivers from blu biker blan years ago. (wonder if he's around yet?) They get used for this task. Somewhere there are pics of the hardwood throttle shaft backing block that really improves the odds when removing those. I just ordered some screws that should make good replacements 3mm x 6mm stainless allan head. I'll report in that other thread on how they work.

I realize that

Those screws are like the brake reservoir screws mentioned in t he link they are REAL fussy and the other end has been swaged. It is best to grind off the far end, otherwise the steel screw enlarges the threaded hole in the brass throttle shaft as you unscrew it that is not a good thing. Couple other notes of use in that link. With the block tool behind it the hand impact is the tool to use to break them loose.

The goal was to just loosen and do a bench sync, not so much replace. Which IIRC, as long as not backed out too far could be ok to do.

Hmm, loosen to do a synch? The only time I loosen those screws is to remove the plate so I can change seals. 5twins likes to put the springs and fittings back on snap them shut a few times then finish tighten. I have done that but on the last set I got the plates fully shut, (back off the idle screw so the plate touches the bore all around) center the shaft/plate holes and installed the screws all worked fine.
This bit is marked 8660 PH2 and fits the throttle shaft screw perfectly. I had no problem loosening the screw. These carbs will get rebuilt with new seals "one of these days" .

Yeah, I learned a long time ago that my quality Craftsman screwdrivers did not work as well on motorcycles as the "tool kit" screwdrivers did. So, when I was working on motorcycles I always used the "tool kit" drivers.

I was the buyer for the Do-It-Best hardware section of a lumberyard. We sold these drivers 382299 https://www.doitbest.com/search?utf8=✓&category_id[]=543d6f8ad9afb9f8da00001f&q=382299&button=search I have had one for almost 30 years, I can't say enough for the quality of these drivers. I have had sets and other good brands of multi use drivers, they stay in the tool box and the Do-It-Best driver is the one that I use, even works well where a JIS should be used. When I took over the buyer's job these drivers had not been stocked for a while, All of the contractors were asking why they weren't in stock any more, found out they were only available in 12's and the previous buyer was tired of ordering 4 or 5 and getting 4 or 5 dozen. Soon I was selling more than a dozen a week, sometimes 2 dozen a week. People who had bought and used them were buying them for other people.

Scott