NASA goes metric

[Xygen]

Isn't km/h already on US speed indicators? In small figures?
That's the same as with Horsepower and Kilowatt here in Europe. First kW was stated in brackets after the HP value. Today it's inverted. A car has 132 kW (200 HP).

 

[Xygen]

Another thing: When we talk about fuel consumption here in Europe, we talk about Liter/100km not miles/gallon. So it's not only the unit: Thinking of miles/gallon represents the thinking of higher=better. It's seems in Europe people think smaller/lower=better.
Do you know what I mean? No offense! That just shows the difference in thinking.

 

[chris_m]

try dividing 7' 5 16/64" into 3 and see how far you get... :green:

In my head 2' 5 3/4" (took about 30s) :nana:

Not sure whether here in the UK we have the best or worst of all worlds - beer in pints, distance in miles, people's height in ' " , people's weight in stones (not sure if you understand that) and lbs, babies weights in lbs and ozs. However we've now been forced by the EU to weigh food in kg and buy milk in litres (though 568ml cartons!) and fuel in litres (though most of us still work out mpg). Meanwhile anything engineering has been done in metric for many years now - which is the way it should be. Though I was taught workshop skills by guys who still talked about "taking a thou off" even if all the machines were metric. Oh, and wood sizing is still imperial even if they quote measurements in mm, and if I was talking to a craftsman about sizing I'd still say "about 2 foot by 4 foot". Is interesting to belong to a generation where you can use metric and imperial interchangeably and I can do most conversions in my head - I imagine the next generation probably don't understand most of the imperial stuff, as for them it's always been metric.

 

[Eugene]

How do you figure? That's purely a function of thread pitch that you can get fine/course in either. Also you have to remember that a grade 8 US bolt isn't as grade 8 metric bolt.

Personal unscientific testing but take a couple bolts the closest you can get in size, thread pitch, grade, etc and clamp the nuts in a vise and put a torque wrench on the heads of the bolts and tighten them down and keep going until they strip and the metric will strip at a lower torque. I found the reason somewhere once on a web site where they explained all the little details about thread pitch and the standards used when metric bolts were developed were a trade off between ease of machining and strength, it was something to do with the actual cut of the threads how they were more straight down into the valleys where the sae threads were arced a little bit.

 

[gadget_lover]

The thread profile of metric and SAE threads are essentially the same. 60 degrees.

There are a lot of places where you can get details. you can see a thread profile at http://www.tanj.com/cgi-bin/tpi.cgi

As mentioned, the grades have different standards in metric and SAE, so that's probably the reason that you experience the failure on the metric screw first.

Daniel