For the Metric Peoples of the world...

[Piglet]

A question about tools that me and a coworker were wondering about. I've been working on more and more Euro-built LSA's, and have been building up my metric tool kit this past year. In the US, when one buys sockets in metric, they still fit 1/4 or 3/8" drives. In Europe or Asia, do metric sockets fit the same drives, or are they, say, 6mm and 9mm drives?

[Bjoern]

I'm trying my best to understand what you're on about, but I'm running into the (technical) language barrier like a parrot into a mirror.

You can order stuff here in inch as well, if that's what you want to know.
If it's purely about the math, then no, your 0.25 inch socket and the 6mm drive won't fit.
However, as I said, it's most probable that the european company knows the socket with its imperial 0.25" size instead of the 6.xyz mm one because "a quarter inch" sounds way more rational than "six point ...millimeters".

[HighGround22]

.
Kinda reminds me:

Aeons ago, when Canada "went Metric", I remember thinking at the time of how dumb a move that was! Metric just didn't make much sense to me at the time. How things have changed.

Given the chance now, I wouldn't revert to "that other system" for love nor money! It was just my resistance to the cerebral change-over that was holding me back. For a logical mind, Metric is The Way.

Sigh. Now if only we could get the US to quit exporting those pea-pickin' half-baked Phillips screws, and give the world Robertsons, the way the gods intended . . . .
.

[djscoo]

.
Sigh. Now if only we could get the US to quit exporting those pea-pickin' half-baked Phillips screws, and give the world Robertsons, the way the gods intended . . . .
.

My high school shop class was the only place I've seen square bit screws. That was all we had.

[demorier]

Don't know about Europe or Asia but in Australia we have the metric system and although the socket size may be metric the drive sizes are still in imperial. 1/4, 3/8 or 1/2" usually.

[Willy]

When I was living in Belgium, their sockets fit my ratchets just fine.

[robert41]

My big problem with metrics is when working on heavy trucks like the Volvo or the Mercedes Engine, you find the same size bolt with different head sizes on it. For example, the exact same part on the motor of one truck has a 12mm head and the next truck it will be a 13mm head. The same motor, same part, same size bolt but different heads on them. In the US system, a 3/8 bolt uses a 9/16 head always.

[Moparmike]

My big problem with metrics is when working on heavy trucks like the Volvo or the Mercedes Engine, you find the same size bolt with different head sizes on it. For example, the exact same part on the motor of one truck has a 12mm head and the next truck it will be a 13mm head. The same motor, same part, same size bolt but different heads on them. In the US system, a 3/8 bolt uses a 9/16 head always.

SAE fasteners don't always use the same size head. There are the occasional oddballs in the bunch just like metrics.
7/16" hex-head is a good example...you will usually have a 5/8" hex head, but occasionally it'll be 11/16". 7/8" and 15/16" bolts commonly come in two head sizes too.
Here at work we get our bulk fasteners (nuts n bolts) from a global industrial supplier that I won't name. From that same supplier we get some different size heads from lot to lot...and they'll even have the same part numbers on the boxes!

Back to Tim's question about european ratchet-type tools. All the ones that I've seen have been SAE size square-drive...except for a few 3/8" hex drive, but I know these are not the norm.

About half of the equipment in our plant is non-US built, so we've got stuff with SAE and metric fasteners, shafts, gearboxes, etc.
The ones that get real annoying are ones that mix and match SAE and metric on the same machine. That's just like turning wrenches on a modern "US-built" car...you need both systems and it's always a guess what is what. GRRR!
I grew up around that mix-n-match problem with my Ski-Doo snowmobiles (Canadian-built but with Austrian-built Rotax engines) and GM cars...so I'm used to it. It's still frustrating though.

[Moparmike]

.

Sigh. Now if only we could get the US to quit exporting those pea-pickin' half-baked Phillips screws, and give the world Robertsons, the way the gods intended . . . .
.

Heh...I'll take those half-baked Phillips (or it's asian counterpart the posi-drive) over a regular flat-head any day. I've got way too many scars on my hands from flat-heads slipping out of those darn slots.

BUT...I do agree with ya that Robertson (square-drive) is the cat's meow for having drivers not strip out or slip out of the screw head.
Like djs said, about the only place you see em here in the states is in the woodworking trades and (finally) we're starting to see more in the electrical trade now too.

For the love of pete though...please outlaw those darned small Torx (anything under T15) drivers!!!
I've twisted off more torx screwdriver tips off in five years than I've rounded out Phillips drivers since I was a kid!!!
Just to change one headlight in my Nissan pickup, I need a T10, T15, and a T20! WHY!!! :d

[Piglet]

Interesting!
The hardware we use is mostly AN or NAS stuff, with the metric equivalent for the Euro light sport aircraft. So the quality is a cut above Home Depot Cheapo, or car stuff. Once in a while we come across some bulldozer/shipbuilding hardware some owner put on!:isadizzy:

[Tom Clayton]

I live in a mobile home that was built almost exclusively with #2 Robertsons! On a side note, try going to any big box hardware store and asking the kid in the tool department for a pack of #2 Robertson bits. You're darn lucky if they know what you're talking about. Since Robertson was originally a brand name, the package just says "Square Drive" - even though they're stamped with "R2" on the bits. It's exactly the same as buying #2 "Cross Drive" bits with "P2" stamped on them - Phillips is a brand name and you can't use it without paying them royalties!

[srgalahad]

Having lived with the dual Imperial/metric issue most of my life, I've never run into a problem using 1/4" thru 1/2" drives with metric sockets. Cheap tools will be sloppy no matter what they call the sizes, but the good ones seem to fit just fine with little or no play and all I can find indicates that the metric drives actually have the male end made to a 'metric equivalent' of 1/4, 3/8 or 1/2", not 6, 9 or 12mm.

Slipping off again to the Robertson discussion, here are a couple of links for those who have never seen the beastie...
http://www.robertsonscrew.com/index.html
http://www.tackaberrytimes.com/default.asp
http://www.mysteriesofcanada.com/Ont...son_screws.htm

A lot of the "square drive" screws filtering into the market today, while not infringing on a patent (which expired) are not made the same.. they have a straight side to the well and/or no taper at the bottom. Although they drive the same, they won't hold a screw on the driver as well which cuts down the 'one-handed' benefit. As well, now that the market is getting flooded with cheap imitations, buyer beware.

As you can see in the third link, it's partly a case of marketing triumphing over design ( and once again ole Henry Ford gets in the picture )

Rob

[kilo delta]

Don't know about Europe or Asia but in Australia we have the metric system and although the socket size may be metric the drive sizes are still in imperial. 1/4, 3/8 or 1/2" usually.

The same here in Ireland and the UK.