But a "trade name" in metric is just fine since the socket drive size is used to distinguish the smaller drives from the larger ones, not for the precise dimension of the drive (i.e. use sockets for a 6 mm drive wrench to do delicate work and keep the 6 mm drive sockets separate from the 13 mm drive sockets). Using metric nominal drive sizes gets people thinking metric as opposed to inch-pound.
This is similar in concept to the idea of calling a piece of lumber a "2 by 4" when its true dimensions are not; the label is nominal and is used to distinguish that size from, say, a "4 by 6". -- Ezra ----- Original Message ----- From: "John M. Steele" <[email protected]> To: "U.S. Metric Association" <[email protected]> Sent: Sunday, September 4, 2011 4:23:13 PM Subject: [USMA:51073] Re: US should weigh up one vital change Maybe as a "trade name." My 1/4"-drive sockets would fall off a 6 mm square drive and my 1/2" sockets wouldn't fit on a 13 mm square drive (interference fit.) 19 mm is so close to 3/4" (50 µm) that it would probably work. On a sample of one drive and a few sockets, my 1/4 drive is about 6.3 mm and the socket drive openings 6.4 mm. A spring loaded ball secures the socket to the drive. --- On Sun, 9/4/11, Michael Payne <[email protected]> wrote: From: Michael Payne <[email protected]> Subject: [USMA:51068] Re: US should weigh up one vital change To: "U.S. Metric Association" <[email protected]> Cc: [email protected], "U.S. Metric Association" <[email protected]> Date: Sunday, September 4, 2011, 9:54 AM Over in Germany I've seen the 1/4", 1/2" and 3/4" ratchets referred in store dispays to as 6, 13 and 19 mm ratchets. I'm not at home to measure one but a tolerance of 0,5 mm is fine for the size of a ratchet. Mike Payne On 30/08/2011, at 20:41 , Kilopascal wrote: I can see where using inch trade names for the ratchet handles can lead to confusion. One way to solve the problem is not to use a number designation at all. Since there are only three sizes with dimensions of 6.5 mm, 9.5 mm and 12.5 mm, they can be referred to as small, medium and large. If you must call them by a dimensional trade name, use the metric numbers of 6.5, 9.5 and 12.5. One thing I like about the Chinese, they aren't hung up on exact conversions from USC. They do a hell of a lot of sensible rounding. This makes everyone happy. The Americans still think they are getting a real inch product. The Chinese round everything to a round metric size before manufacturing and the American consumer is totally unaware. Having the Chinese build American products assures the products are properly metricated to rounded sizes. [USMA:51044] Re: US should weigh up one vital change John M. Steele Tue, 30 Aug 2011 12:26:36 -0700 I believe he is referring to the rachet handles (the square drive dimension that the sockets connect onto) and not the bolts that the sockets fit. --- On Tue, 8/30/11, Michael Payne <[email protected]> wrote: From: Michael Payne <[email protected]> Subject: [USMA:51043] Re: US should weigh up one vital change To: "U.S. Metric Association" < [email protected] > Date: Tuesday, August 30, 2011, 3:01 PM A 1/4 and a 3/8 you might need, but the 1/2 is so close to 13 mm it should not matter. Turns out the 10 mm and 13 mm are quite common bolt/nut sizes. The 10 mm will fit a 3/8 bolt but might be a bit loose. The 1/4 inch used to be a common appliance size bolt, but now they are all made in China or Korea the 1/4 will not fit anymore. Mike Payne On 29/08/2011, at 15:39 , [email protected] wrote: > China is defiantly benefitting from our ignorance, if you have a Harbor > Freight store in for area, you would know it is 100% China made products, I > am defiantly boycotting this store, they sale mostly 'English' tools, no > Metric drills of any sort, and some Metric tool sets. People think they are > saving money there, but you are buying two sets of tools. No thanks, no more > Imperial tools for me, but still need to buy 1/4, 3/8, 1/2 socket set as I do > not know of any Metric versions. > > > Bruce E. Arkwright, Jr > Erie PA > Linux and Metric User and Enforcer > > > I will only invest in nukes that are 150 gigameters away. How much solar > energy have you collected today? > Id put my money on the sun and solar energy. What a source of power! I hope > we dont have to wait til oil and coal run out before we tackle that. I wish I > had a few more years left. -- Thomas Edison♽☯♑ >
