American screws drive me nuts!

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#221
I have this problem too. I need 8 M6x15 mm screws. But the formers are between M5 and M6 and the helecoidal tap is more relaxed than european metric bolts.
I even dunno where to look for on internet and how it is named...

Ah and I notice in USAthe water flows in circle in the lavabo on the wrong direction... I do not know how it flows in the international space station ? Btw perhaps they pee towards the ceiling ?!
 
#222
simon7000 said:
Now to stay on topic, we can discuss where U.S. bolts and machine screw thread sizes started.

Andrew Carnegie did well making steel. However actually being an astute businessman he sought to increase his steel sales and realized he could do so by making and selling bolts! So his company latter to become U.S. Steel came out with a range of offerings. Being cost concerned his fasteners came in a standard range of sizes and one thread pitch for each diameter . For example a 1/2” bolt would be offered only in a pitch of 13 threads per inch.

Later the Society of Automotive Engineers offered a standard bolt sizing system. Their 1/2” bolt standard called for a thread pitch of 20 per inch.

As things overall got standardized there became “National Course” thread standards which were based on the bolt sizes by the steel makers and “National Fine” sizes which were the SAE sizes. To accommodate any other common sizes they became “National Special.”

I keep on hand machine screws from 2-56 to 10-32 and bolts from 1/4-20 to 1/2-13, of course along with the matching nuts and washers. I think a bit more than 300 sizes in all. (Length matters also!). I do not keep sizes known here as “Stove Bolts”. I do have a shelf of metric sized bolts that are commonly used around here.

My useful accomplishment was to build portable carts with enough shelves and compartments to hold and display the assortment, so there was no hunting for any box of bolts! Now if I can only get folks to put things back where they belong.
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It's UNC, UNF and UNS (Unified National Coarse, Unified National Coarse and Unified National Fine). Unified thread standards are the First standardized thread dimensions the UK, US and Canada agreed upon. I prefer the metric system, but it isn't up to me.
 
#223
The standard started a bit after the U.S. Civil war, becoming well entrenched around 1920. SAE entered the fray after 1905. However due to WWI it became a joint standard with the British, and of course the Canadians (1948). These days it is just called the Unified Standard by most folks spelling it out.

I do have some bolts from the late 1800's mostly square head, 60 degree taper (More probably 59 degrees!) but still sized 1/4-20. Next up why a 1/4" bolt is actually not .25" and the thread on bolts is cut at 59 degrees!
 
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#227
kodabmx said:
I always wondered why UK decided that you should shift gears with your left hand... Most people are right handed.
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Its more of a question for today`s cars where you have touch screens and lots of options to work on with your left hand...

Maybe it was done so if the Axis powers ever landed on British soil, they`d all die in car accidents before reaching London. The most feared would be the double roundabout 😀
 
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#228
IMG_20221111_092017.jpgWhy have one set of metric drills, when you can have fractional, number and letter drills ?
IMG_20221111_092017.jpg
 
#230
Clark's Tables, 1979 edition....tell the publisher about it, they were British too.
It seems 1 Billion is 10 E9 if you speak English, including the UK from 1974.
Before 1974 it was 10E12 in UK also.
It is still 10E12 in Europe, Brazil, and other non English speaking countries.
 
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#231
Copper plumbing pipe.
15mm O.D. In the UK. 15.9mm O.D. in N. America.
My pipe fittings don’t fit, my pipe cutters don’t work. Even my unwieldy pipe bender that I hauled across the ocean doesn’t work anymore. I have a box of unusable parts and tools. How senseless is this?

And why is copper spec’d by O.D. and plastic pipe by I.D.? Buy a 2.25” hole saw for a 2” pipe and you’ll also need to buy a rasp. Fortunately, I already had a rasp.
 
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#237
traderbam said:
Copper plumbing pipe.
15mm O.D. In the UK. 15.9mm O.D. in N. America.
My pipe fittings don’t fit, my pipe cutters don’t work. Even my unwieldy pipe bender that I hauled across the ocean doesn’t work anymore. I have a box of unusable parts and tools. How senseless is this?

And why is copper spec’d by O.D. and plastic pipe by I.D.? Buy a 2.25” hole saw for a 2” pipe and you’ll also need to buy a rasp. Fortunately, I already had a rasp.
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Copper and steel pipe use O.D. measure because fittings are made to fit on the outside ( a steel pipe is threaded on the outside ). So if you makes several grades of pipes with thicker wall the outside is always the same diameter and will always fit same tools & fittings.
 
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#238
Mario Pankov said:
Its more of a question for today`s cars where you have touch screens and lots of options to work on with your left hand...

Maybe it was done so if the Axis powers ever landed on British soil, they`d all die in car accidents before reaching London. The most feared would be the double roundabout 😀
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What a poor show. We have magic roundabouts in UK. The traffic goes round in both directions.
Any driver that hesitates gets high on them like as if they have been eating naughty mushrooms.
If the town has the word high in the name it is vital that they have a magic roundabout for the hesitant drivers can get on😀
https://www.google.com/maps/@51.6270145,-0.7507942,134m/data=!3m1!1e3!4m2!10m1!1e1
 
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