That state of metric conversion in the US

Everything doubles in size, because they make one squint? Heheheheh...

In California you can get asterisks. Even heart shapes AFAIK. It's crazy out here.

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Regards, Joerg 

http://www.analogconsultants.com/

Not sure what you mean but I mostly deal with the ones used by cardiologists. Folks on the table are usually fairly quiet when that's done.

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Regards, Joerg 

http://www.analogconsultants.com/

{shudder} I do like the metric version better 3x10E8.

I wouldn't mind at all going 100% metric. Even if I work in metric, that is easier to incorporate Imperial units (is the inch really considered "Imperial"?) since the conversion is well defined. If I were working in inches and needed to use metric items the conversion doesn't work out so nicely, dividing by 2.54 is a lot uglier than multiplying.

Do you think a 6 mm square head isn't going to work ok with a 6.35 mm square socket hole? I don't think the 0.35 mm difference (if it is that much) will even affect the detent. Am I wrong about this? I expect a square connection would be much more forgiving of size mismatch than a

12 point socket on a hex nut.

Sounds like a good reason to just give in and spend the extra few bucks to get the metric stuff. I wonder how the rest of the world manages? It much be a PITA knowing they are paying too much for their tools.

There are plenty of times when I get tired of trying to do the math on feet, inches and binary fractions of an inch. Where do I mark cuts on a board 3 ft, 3 3/8 inches long to space out three notches 1 5/16 wide so the un-notched areas are all the same width? With all round metric values I can do that in my head. 33 1/3 mm notches and 225 mm un-notched areas.

I remember conversion cards to go between decimal and fractional inches. I've never seen anything like that for metric. Living in the metric world is the best way to go, living in both worlds is the worst way to go.

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Rick

A nautical mile is a minute of arc on the great circle. It just happens to be about 6000 feet.

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Tauno Voipio

I looked at 3 datasheets on digikey, they all say the hex is 11mm. the thread's not metric though, 3/8-32UNEF-2B

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?? 100% natural

Tim Williams schrieb:

Hello,

but if 1/4 = 6.35 mm is too thin and 3/8 = 9.53 is too thick, there is also 5/16 = 7.94 mm or 9/32 = 7.14 mm. If you want something like 5 mm, you may specify 2/10 inch which is 5.08 mm. 4/10 is 10.16 mm and 3/10 is 7,62 mm. If they want to divide by powers of two, no problem, 13/64 is 5.16 mm.

19/64 is 7.54 mm. If more precision is needed, 1/256 is 0.09921 mm, 50/256 is 4.96 mm.

Just a little flexibility.

Bye

Yup. Most are dimensioned in hard metric (11mm across the flats).

Pomona's data sheet shows 7/16, which they dimension to 0.43 in decimal inches (rather than 0.4375), and convert to metric at 10.92 (7/16" is exactly 11.1125mm). Sigh.

FWIW, the nominal dimension given on hex nuts seems to be the maximum, with tolerance allowed on the less-material side. I'm sure there's some DIN standard, as there is a standard for Imperial dimensioned external flats.

Best regards, Spehro Pefhany

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"it's the network..."                          "The Journey is the reward" 
speff@interlog.com             Info for manufacturers: http://www.trexon.com 
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

years.

Even more fun are Allen keys and hex keys. Those generally require the utilization of the exact correct and proper tool to properly torque the fastener and also not ever damage it.

Even with a Philips head screw, one should use the correct size, and make sure the insertion force is applied correctly before torqueing in either direction.

The radiation center heights above mean sea level and above ground level are stated in meters. The predicted distances to various field strength contours are in kilometers. Luckily meters X megahertz = 300 has always been true.

This happens a lot does it?

Not to mention the Japanese standard (JIS) "not quite" Phillips head that doesn't properly fit Phillips drivers. The JIS screws usually have a dot on the head. The Japanese design depends on torque limiting in the driver, wheras the older Phillips was deliberately designed to cam out.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward" 
speff@interlog.com             Info for manufacturers: http://www.trexon.com 
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

And then there's "Pozi"...

A company I worked for which sold serviceable equipment partly to the US had a policy of slotted screws only to save grief.

Cheers

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Syd

Exactly, which not many know.

Not now, however. One is supposed to attempt to keep the screw head pristine. that requires strong insertion force and a proper torque limiting tool.

Nealy all "cam out" events also include a "buggered up" screw head thereafter.

Approximately. A minute of arc is slightly less than 1 nm at the equator and slightly more just shy of the poles. About a 1% change overall [Bowditch 2002, Table 7]. You're correct, though, that for practical navigation purposes, using one's dividers on the latitude scale of a Mercator projection yields distance in nm. And yes, it is just a happy coincidence that it works out to be roughly 2000 yds. Handy, though.

I thought he was living in a KFC dumpster?

y y e

I once found a US Army specification for a piece of electronics equipment that listed the maximum weight in grams and the maximum dimensions in inches.

Off-topic a bit, but I have copies of two successive pages in a US Navy spec. On one page, all that is written except for the document header and page number is "This page intentionally left blank". The next page just has the document header and page number.