General > General Technical Chat
why is the US not Metric
SilverSolder:
--- Quote from: KL27x on February 13, 2020, 07:33:08 pm ---
--- Quote ---It's the same drill we are talking about, we just call it something more meaningful to us.
--- End quote ---
To be honest, imperial drill bit sizes are not all that meaningful even to me. Anything beyond 8ths, I tend to just measure the screw/pin/dowel with calipers, then find the drill bit with calipers, lol.
There's also the time-tested trick of holding the screw and drill bit together, to see that the threads of the screw are just visible behind the silhouette of the drill bit. :)
--- End quote ---
You haven't lived until you've owned a complete American drill set, including Fractional 1/16" to 1/2" by 64ths, Letter size drills A - Z, and Number size drills No. 1 - 60!
Really all these could usefully be rationalized to metric sizes, so you don't have to refer to a chart to figure out what is going on every time you need to drill a precise hole...
DBecker:
--- Quote from: SilverSolder on February 13, 2020, 07:47:15 pm ---
--- Quote from: KL27x on February 13, 2020, 07:33:08 pm ---
--- Quote ---It's the same drill we are talking about, we just call it something more meaningful to us.
--- End quote ---
To be honest, imperial drill bit sizes are not all that meaningful even to me. Anything beyond 8ths, I tend to just measure the screw/pin/dowel with calipers, then find the drill bit with calipers, lol.
There's also the time-tested trick of holding the screw and drill bit together, to see that the threads of the screw are just visible behind the silhouette of the drill bit. :)
--- End quote ---
You haven't lived until you've owned a complete American drill set, including Fractional 1/16" to 1/2" by 64ths, Letter size drills A - Z, and Number size drills No. 1 - 60!
Really all these could usefully be rationalized to metric sizes, so you don't have to refer to a chart to figure out what is going on every time you need to drill a precise hole...
--- End quote ---
As the owner of several index set, I don't see any way to make them substantially simpler. You'll still need a machinists handbook to figure out the proper one to use. What is the proper size drill to use for a M10 fastener? That depends on what you are doing. If you are going to tap the hole, you need to consider the thread type, thread pitch, fit, tap type and material. You might find that you need an R drill, which turns out to be more useful than "8.65mm" when that's not a common size.
The number and letter drill sizes are equivalent to the E series for resistors. If you want a 5-ish ohm resistor, you select 4.7 or 5.1 ohms.
SilverSolder:
--- Quote from: DBecker on February 13, 2020, 08:45:20 pm ---
--- Quote from: SilverSolder on February 13, 2020, 07:47:15 pm ---
--- Quote from: KL27x on February 13, 2020, 07:33:08 pm ---
--- Quote ---It's the same drill we are talking about, we just call it something more meaningful to us.
--- End quote ---
To be honest, imperial drill bit sizes are not all that meaningful even to me. Anything beyond 8ths, I tend to just measure the screw/pin/dowel with calipers, then find the drill bit with calipers, lol.
There's also the time-tested trick of holding the screw and drill bit together, to see that the threads of the screw are just visible behind the silhouette of the drill bit. :)
--- End quote ---
You haven't lived until you've owned a complete American drill set, including Fractional 1/16" to 1/2" by 64ths, Letter size drills A - Z, and Number size drills No. 1 - 60!
Really all these could usefully be rationalized to metric sizes, so you don't have to refer to a chart to figure out what is going on every time you need to drill a precise hole...
--- End quote ---
As the owner of several index set, I don't see any way to make them substantially simpler. You'll still need a machinists handbook to figure out the proper one to use. What is the proper size drill to use for a M10 fastener? That depends on what you are doing. If you are going to tap the hole, you need to consider the thread type, thread pitch, fit, tap type and material. You might find that you need an R drill, which turns out to be more useful than "8.65mm" when that's not a common size.
The number and letter drill sizes are equivalent to the E series for resistors. If you want a 5-ish ohm resistor, you select 4.7 or 5.1 ohms.
--- End quote ---
Sure, but say you need something slightly larger than an F size drill bit. Will that next size up be a letter size, a number size, a fractional size, or even a metric size?
I ended up making a spreadsheet that translates all the sizes to metric, and sorting them by their metric size, then printing it out as a chart that I keep in the shop. Nice and logical!
CatalinaWOW:
I have the same sorting chart in decimal inches. Yet another case where metric is slightly better, but not enough to force a change.
SkyMaster:
--- Quote from: Gromitt on February 13, 2020, 12:56:38 pm ---
--- Quote from: SkyMaster on February 13, 2020, 02:28:10 am ---
--- Quote from: Tepe on February 12, 2020, 09:27:51 pm ---
--- Quote from: forrestc on February 12, 2020, 05:13:49 pm ---The one major area where pretty much every country in the world has not metricated is aircraft flight levels.
--- End quote ---
Note the altimeter in this Saab J35 Draken ("Höjd m"):
--- End quote ---
Except for some communist countries, nobody in the world is using meter as an altitude unit in aviation.
:)
--- End quote ---
You mean countries with the same level of communism as Canada? :P
--- End quote ---
What are you talking about?
???
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