Why are SAE sockets formatted in fractions?

[Rmay635703]

9/16" also but 9/16" is kind of considered a "specialty" or "automotive" size and sometimes only at true fastener houses -- although I've seen it in Hillman stuff at my Ace Hardware. Many smaller "hardware" stores jump 1/2" to 5/8"

I checked over a dozen of 7/16” studs in the system and they all use 5/8” sockets.

I’m guessing the “other” sizes are the antique light medium heavy fine/coarse “nut” crap used in AG? I would have to check but probably deprecated from SAE (50’s)
or listed as an alternative size for square hardware.
(Nothing like USS not equaling SAE)

So What application?

Now very very old (obsolete) 1/4” hardware comes with an alternate size head, (system has prints from 1952) but that other size is deprecated from SAE standards, though square head bolts still exist in some sizes which drives some weirdness for wrench/socket sizes.

 

[vavavroom]

Socket drives are in inches in Imperial and later SAE and Metric because the square socket drive was an American invention of the 1860s and they became a worldwide standard. For compatibility reasons the Imperial drive standard has been maintained globally.

The Metric system predates the Imperial system but the old English system on which the Imperial system is based by far predates the Metric system.

Systems of measurement are a bushel of fun. A US bushel and an Imperial bushel are not identical.

 

[Number_35]

related question- why is the denominator always a power of two? what happens if i run into a 2/3 inch hex nut? i'm HOSED, that's what!!!

Don't you have a 1.33/2 socket?

 

[CheezWhiz]

really everything should be torx ... i love torx ...

 

[mitch1]

i must be the only one that remenbers old ford flatheads. I still have 19/32, 21/32, and 23/32 sockets. They were used on the rod bolts and main caps. And the old favorite from a odd german brand, a 20.8mm spark plug socket.
And the old question , why 7mm?
as far as I know only the French used 7mm bolts and nuts.
Or Air cooled Vw's, 11mm for the distributor hold-down.

 

[warnerwh]

I can't imagine how anyone could graduate high school with out knowing fractions. Fractions are taught in grammar school. It would make life harder not knowing fractions as they are used all the time in numerous ways. Schools and teachers that let students graduate high school that don't even know fractions are a disgrace imo.

 

[ZeeOSix]

I can't imagine how anyone could graduate high school with out knowing fractions. Fractions are taught in grammar school.

Those are the people that say "cut that pie into 0.33333" instead of "cut that pie into 1/3s".

 

[CheezWhiz]

I can't imagine how anyone could graduate high school with out knowing fractions. Fractions are taught in grammar school. It would make life harder not knowing fractions as they are used all the time in numerous ways. Schools and teachers that let students graduate high school that don't even know fractions are a disgrace imo.

i was pretty good at differential equations. i don't want to have to solve them just to replace my alternator!

 

[Rand]

This is totally one of those sitting on the toilet pondering life questions but it’s stuck in my head.

my 2 cents:
I'm going with "ever look at a tape measure"
as the reason

 

[Speedbird001]

 

[drtyler]

i was pretty good at differential equations. i don't want to have to solve them just to replace my alternator!

What do differential equations have to do with fractional measurements?

 

[CheezWhiz]

What do differential equations have to do with fractional measurements?

no one wants to do math, we just wanna fix cars!!! doesnt matter what kind of math, that's all i was trying to say.

 

[cdlamb]

SAE would be easier if they didn't simplify the fractions and left every with 16 as the denominator. Instead of 1/8, 3/16, 1/4, 1/2... you'd have 2/16, 3/16, 4/16, 8/16, etc.

How about like a rain gauge & measured in tenths of an inch.
then we would need a metric set an imperial set,
& another set for the new format.

Fractions of an inch don't bother me.

 

[JeffKeryk]

I've read all these 133 posts and still don't understand the question. SAE standards started in the early 1900's, right? It is what it is.
I used to think Metric was stupid. Now my SAE tools are pretty much put away...

 

[Pew]

Sounds like something from a Facebook post that is 100% false. I have school-age children.

It is still taught in 1st and 2nd grade but it doesn't sound cool if people don't complain about a situation they made up in their heads.

 

[Pablo]

Sounds like something from a Facebook post that is 100% false. I have school-age children.

Depends on the school district and state

 

[Hall]

Depends on the school district and state

Doubtful.... School districts have to teach the curriculum their state BOEs dictate. What states don't mandate teaching fractions ?

 

[Hall]

I used to think Metric was stupid.

American here - the metric system is far, far superior, logical, and easier to use.

 

[Pablo]

Doubtful.... School districts have to teach the curriculum their state BOEs dictate. What states don't mandate teaching fractions ?

Not sure on the mandate. It is up to the state. They certainly don't emphasize teaching fractions. Are they required to teach fractions? I don't know. But again there isn't much time/dwelling/repetition - it's been like that for awhile and it shows.

Fractions: Where It All Goes Wrong

Why do Americans have such trouble with fractions—and what can be done?

www.scientificamerican.com

 

[ZeeOSix]

American here - the metric system is far, far superior, logical, and easier to use.

You haven't lived until you can do physics, mechanics of motion and thermodynamics in both SI and SAE/Imperial units.