Do you realize that the SAE has standards for metric tools and fasteners also? So they are all really SAE. Now inch vs metric could be a discussion...

Honestly though seems the people that ask these questions must do an extremely limited amount of tool work. I don't see it going away anytime soon. Almost everything down our greenhouse business from the building frame fasteners to hose clamp screws are all standard fastener sizing. I don't even carry metric wrenches in my tool bucket around there
And generally the tractor 3pt equipment and sprayer parts are all standard fasteners too unless it's an imported brand. On a personal level both my motorcycles and most of my yard equipment have standard hex head fasteners. And even certain shop equipment too mostly because it is older US built stuff
Sure my tractor is JIS, as are my chainsaws and line trimmers as is some of my SUV
And I have sockets and bits for many types of internal and external fasteners but like others are saying they keep evolving those too![]()
Outside of America... Most of the normal stuff is metric as well.
I can't remember the last time I had to use none metric spanners or sockets.
Literally everything is metric.

I bought all new snap on sae 1/4, 3/8 1/2 deep and standards socket sets about five years ago. I may have only used one or two of them. I regret the $$$ I put down. If I could go back, I would have just bought a set of sunex 3/8 deep impacts.
Honestly though seems the people that ask these questions must do an extremely limited amount of tool work.
:I was thinking this exact thing.
For the foreseeable future, there will be a need for all standards of tools. Consider a little historical perspective: Phillips head screws were going to make slot head screws obsolete. Torx heads were going to make phillips heads obsolete. Other styles were going to make them all obsolete. It didn't happen. There are uses for them all, and many others. And there are simply too many out there to expect any short term utility in not being able to service them.
In the early to mid 1970's, there was a huge government push to convert the U.S. to exclusive use of the metric system. In some ways, it succeeded and in others it failed. The end result was the two systems exist in relative harmony side by side. And yet most people don't even realize some of the absurdities this entails. A shopping cart sits with a gallon of milk next to a 2 liter bottle of soda. The one ounce shot of Jack Daniels on the bar is poured from a liter bottle. And your doctor weighs you in pounds before prescribing meds in milligrams. Seems crazy, but it still works.
Same with tools. As we deal more with global standards and production, the need for metric tools will increase, but SAE is not going away. And legacy use will be around longer than any of us.


To add to the gallon of milk, the farmer is paid in another unit of weight: per hundredweight.
I'm not sure how the NFL would work in metric; or buying a 1ft hotdog, do you ask for a 30.48cm dog?![]()
Just got back from an estate sale of a US Air mechanic. Two tool boxes full of SAE tools and hardly any metric tools to be seen. I am assuming Boeing, McDonnell Douglas aircraft from that era were pretty much all SAE?