Why are SAE sockets formatted in fractions?

[Hall]

And I still find some SAE sizes on almost every car or mower

I got a hand-me-down Hustler ZTR earlier this year and went to work on it, well, I couldn't.... Our son took my SAE sockets (well, I guess I gave them to him since I hadn't needed them in years) though I did have a box of random SAE sockets that belonged to my Dad and I managed but still ended up ordering a set.

 

[ripcord]

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

I recently had to work on a project which required me to buy and use SAE sockets. I really only work on fairly modern cars and motorcycles which are by and large metric so never really used SAE. I noticed when grabbing sockets from the box and bringing them over to the workpiece I struggled initially a little with assessing how much larger a socket was in proportion to another because the denominator was different so lost perception of scale, a quick way to solve this would to use decimals. Why don’t they do that? I’m sure there’s a reason and I know if you work in standard all the time it becomes second nature but always was curious why they never just did decimals vs different fractions it seems like it would be easier to delineate between sockets like metric.

Because "0.15625" won't fit on the side of an 5/32nds socket.

 

[97K15004WD]

Has Jet sizes on it too. That's nice!

 

[mrbreezeet1]

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

I recently had to work on a project which required me to buy and use SAE sockets. I really only work on fairly modern cars and motorcycles which are by and large metric so never really used SAE. I noticed when grabbing sockets from the box and bringing them over to the workpiece I struggled initially a little with assessing how much larger a socket was in proportion to another because the denominator was different so lost perception of scale, a quick way to solve this would to use decimals. Why don’t they do that? I’m sure there’s a reason and I know if you work in standard all the time it becomes second nature but always was curious why they never just did decimals vs different fractions it seems like it would be easier to delineate between sockets like metric.

Because most people can't read decimals

 

[D60]

Because most people can't read decimals

I was working in a machine shop where they hired an engineer to be a machinist. In this area skilled labor is hard to find so they figured they could train him up.

He approached me one day and asked why his machine kept shutting down due to overload on a particular op.

He was supposed to be taking 30 thou per cut (0.030") but he had put in 300 thou (0.300") -- nearly 5/16" on a side.

 

[Rmay635703]

We always had a chart of every English, (factional/decimal/gage/penny) sizing by the equivalent metric.

Was in every work center.

Fractions were still taught when I was in school (not as long ago as you might think)

so I’ve never had an issue with fractions.

 

[paulo57509]

My father had three or four really odd sized offset box wrenches (Plumb) - most in 64ths. I think Studebaker used these odd sized fasteners?

I wish he would have kept them; haven't been able to find them in his old roll-away.

 

[JWC86]

1) I remember guys stating that the Canadian plywood they were working with was metric and created problems while building flooring. I never gave it another thought. Any Canadians want to report?

That's BS, Plywood is sold in Canada in fractional Inch sizes. 3/8", 1/2", 3/4", etc.

 

[mrbreezeet1]

I was working in a machine shop where they hired an engineer to be a machinist. In this area skilled labor is hard to find so they figured they could train him up.

He approached me one day and asked why his machine kept shutting down due to overload on a particular op.

He was supposed to be taking 30 thou per cut (0.030") but he had put in 300 thou (0.300") -- nearly 5/16" on a side.

OMG! Lathe or mill? If a lathe so 30 thou cut, and 60 thou off the diameter.

 

[kschachn]

That's BS, Plywood is sold in Canada in fractional Inch sizes. 3/8", 1/2", 3/4", etc.

Reminds me of the similar situation with socket drive sizes.

 

[SHOZ]

I got a hand-me-down Hustler ZTR earlier this year and went to work on it, well, I couldn't.... Our son took my SAE sockets (well, I guess I gave them to him since I hadn't needed them in years) though I did have a box of random SAE sockets that belonged to my Dad and I managed but still ended up ordering a set.

The new JD is metric but 5/16" 1/2" and 9/16" work too.

I see 7/32" is 5.5mm

 

[Rmay635703]

Reminds me of the similar situation with socket drive sizes.

More confusing is when you need to drive a 4pt or 8pt component but only have 12pt tools

 

[JeffKeryk]

Wait until you run up on and old Brit Bike....

Whitworth for the win!

 

[chris719]

There are only two imperial units/scales I have any time for. Fahrenheit because it’s got a higher integer resolution over normal human temperatures, and the “mil” (thou) commonly used in PCB design. Trace widths, pad widths, stack-up thicknesses etc. just seem to be more natural in mils rather than mm. I don’t like fractional quantities apparently.

 

[Snagglefoot]

Here it is. It was the British who came up with the system during the industrial revolution. The system is based on the concept of one half.

Start with one. One half of that is simply 1/2. One half of that is 1/4. One half of that is 1/8. One half of that is 1/16. One half of that is 1/32. One half of that is 1/64.

Then it was just a matter of filling the gaps with 1/32, 2/32, 3/32,4/32 etc.

 

[Pablo]

They used to teach fractions in grade school. Probably not anymore, replaced by some more important gobeldy-gook.

They actually don't teach them. Which messes people up more than thought.

I'll take an eighth of that..........blank look...........

 

[Pablo]

I was working in a machine shop where they hired an engineer to be a machinist. In this area skilled labor is hard to find so they figured they could train him up.

He approached me one day and asked why his machine kept shutting down due to overload on a particular op.

He was supposed to be taking 30 thou per cut (0.030") but he had put in 300 thou (0.300") -- nearly 5/16" on a side.

In defense of engineers..............what kind of engineer was this?

I mean most of us worked in decimals - me for 50+ years (school included). Did he phat finger it or just didn't know? That might explain why he, well......is not working as an engineer.

To be honest, I could not walk up cold to a random CNC machine, punch in some numbers and make a part!

 

[ZeeOSix]

"Why are SAE sockets formatted in fractions?"​

Because it's easier to understand and say "hand me the 7/16 wrench" instead of "hand me the 0.4375 wrench".

 

[dlundblad]

I dont worry about it... I have a complete set of Metrinch that I purchased in 2005 and they are great...They fit both SAE and metric...They grab the walls of the bolt so even if they are stripped at the edges it still grips great to remove the bolt...

I talked to a kid who worked at a junkyard a few years ago. He had nothing but good to say about metrinch wrenches, but he only used them on rounded or rusted bolts. They are very strange looking… They don’t damage a good bolt head?

 

[hrv]

I talked to a kid who worked at a junkyard a few years ago. He had nothing but good to say about metrinch wrenches, but he only used them on rounded or rusted bolts. They are very strange looking… They don’t damage a good bolt head?

Nope they dont damage a bolt at all..back when I purcgased the set some cars still had a mixture of SAE and Metric bolts...This one set took care of both...