who has gone metric?

I use primarily imperial system. Unless the prints are metric or the thing I'm building parts for is metric. I have ready access to imperial machines and tooling. What I don't care for is the use of fractions. IE: I can buy a 3mm to 20mm collet set that is graduated 1mm at a time. It covers the ENTIRE range in between. I can buy the same set in inch and it has holes all over it's range. What utter B.S.!! Why not make them in thousandths and cover the full range like a metric set? So it will be that one of my metric purchases will be collets. The box will be labeled in thousandths as soon as I open it. By the way Europe used to be imperial and faces the same difficulty to a lesser degree. They can get metric tooling cheap and available if they so choose. Those old machines though, they think in imperial. I know metric math is easy, but really what dipstick decides to change everything? Why?
 
All my home shop carpentry and metal working measuring tools are inch-foot-yard.

I have metric wrenches for working on cars, because all autos at my household have metric fasteners. Still don't have any metric drill bits though.

At work, it's nothing but metric because I work in a laboratory. Volumes are liters, weights are grams, and lengths are meters. No other measurement system is used or would be acceptable. However, 1 liter graduated cylinders have 10-mL tick marks, while 2 liter graduated cylinders have 20 mL tick marks. It's best not to confuse the two.

Interesting that time systems are all the same. 10 hour days and 100 minute hours seem feasible, but you can't change the ratio of the Earth's rotation to its orbit. I certainly am not agitating for a 10 day week!

Walt
 
I worked in a lab for a bit too, and most things were metric.
3 km/s was 3 um/us so conversions were quick and easy. the only US measurement we did use was pressure. I have no clue what a Pascal is, but I do get psi
 
anyone who thinks the imperial system is just fine probably only uses linear measurements. in doing scientific work dealing with volumes, pressure, and moles, metric is the only way to do it without going insane.


oh yea. pascal is just like psi. instead of pounds per square inch, you have newtons per square meter. (remember, kilograms and grams cannot be used as force!!!)
 
MCRIPPPer said:
anyone who thinks the imperial system is just fine probably only uses linear measurements. in doing scientific work dealing with volumes, pressure, and moles, metric is the only way to do it without going insane.


oh yea. pascal is just like psi. instead of pounds per square inch, you have newtons per square meter. (remember, kilograms and grams cannot be used as force!!!)
Click to expand...

Or better yet, thermodynamics.... What ins the world is a Themal unit anyways... and why not use the italian one :)
I college, I survived by converting the problem to metric and then putting the answer back into Empirial units when I was done. Thank goodness for that HP48 Calculator (which I still use 20 years later) :)

And then there is my favorite non-metric thermodynamic unit: the Ton of Refrigeration. Anyone want to guess what that is all about... It's the amount of energy needed to melt one ton of Ice in 24 hours... I guess usefull back when we were converting Ice houses to mechanical refrigeration, but I am not sure that the average homeowner has a clue how his AC unit is sized. I also wonder how many plant engineers over designed the mounting for their 5-ton chiller units :)

But in the home shop world, I don't think that absolute measurements are really that important. Since we are usually only making things in single quantities we can all use the Gesinte tolerancing system:
This Gesinte That :)
 
Here is the photo of something curious I took in a medieval town not far from here: old measures used by the Republic of Genoa before the "metrication" by Napoleon I.

genoese_measures.jpg

The sign can be roughly translated as:
Ancient Public Standards of Genoese Measures
Cannella: m 2.22 » 9 palms
used for fabric, rope, etc.
Canna: m 3.504 » 12 feet
used for walls, parcels of land, etc.

Wikipedia has two interesting articles about this:

https://en.wikipedia.org/wiki/History_of_the_metric_system

https://en.wikipedia.org/wiki/Metrication

Another thing to raise your hair: modern land surveying measure angles using the "gradian" (400 grads a whole turn) rather than the most common degree (360 degrees a whole turn).
It is faster to make mental calculations, but common angles (30° and 60°) become pretty fractional (100/3 and 200/3).

https://en.wikipedia.org/wiki/Gradian

For a good laugh, the mayor of a small town told he will face a problem with a 365 degrees point of view…
:roflmao:

genoese_measures.jpg
 
Marco Bernardini said:
The sign can be roughly translated as:
Ancient Public Standards of Genoese Measures
Cannella: m 2.22 » 9 palms
used for fabric, rope, etc.
Canna: m 3.504 » 12 feet
used for walls, parcels of land, etc.
Click to expand...

The next time I drop by one of the big box hardware stores I'm going to ask for 30 palms of rope & see how much I get. :rofl:
 
toag said:
I worked in a lab for a bit too, and most things were metric.
3 km/s was 3 um/us so conversions were quick and easy. the only US measurement we did use was pressure. I have no clue what a Pascal is, but I do get psi
Click to expand...

A Pascal is the French preference to measure pressure. The bar is used in the UK and,of course, the pound is preferred in the US. With vacuum Torr was the preferred unit until The French & the Brits decided to "revolt". Torr is based on Torchelli who we remember for inventing the barometer and who wasn't any of these other guys. Ironically Torr is based on millimeters. 1 Torr is 1mm of mercury which is what Torchelli used in his barometer. It's the vacuum measure I've liked to use since 1957 !
 
Metric system is usually easier for solving the math, but I don't know by feel what a newton meter is. I can guess what 12 ft pounds of torque is with an eight inch wrench. I can see 1/4 mill in my head, and I know what a 200 yard shot is. But that's what I've grown up with.


Sent from my iPad using Tapatalk
 
I dont see how one is easier then the other. Both are just numbers. Both can be as precises as you care to take them. I often use metrics for tap drills for standard. If your looking at fractions, well those are a pain till the light goes off in your head of the way they work. They seem dumb as the numbers dont flow in line lie decimal or mm. But who measures 15/16 anyways you measure the decimal
 
You must log in or register to reply here.
Back
Top