SAE vs Metric

[Rust_Belt_Pete]

I was looking for deals on sockets sets and noticed that it is almost always SAE and metric.
All of my cars are metric, pretty sure my appliances use metric too where they use bolts and nuts.
I am curious do you use Metric or SAE more often?
What is SAE commonly used on?

 

[Propflux01]

SAE is slowly dying out. Used mostly on older equipment.

 

[Langanobob]

I have the same issue and I don’t know why they insist on packaging metric/SAE combo sets. I have some older USA vehicles and machines but I have more than enough SAE wrenches for them, don’t need any more.

 

[Timmastertech]

Mostly use SAE on rusted metric hardware and odd fasteners here and there like some brake line fittings, bleeder screws, etc. That said, to put in perspective how often that stuff gets used anymore, while all of my metric tools are tool truck brand and I have multiple sets and about every combination you can think of, I have no duplicates in SAE, never bought swivel sockets or impact sockets, and most are still the craftsman and husky tools I bought starting out 20 years ago

 

[Cujet]

Working on a Polaris 330 Trail Boss today. It is made with SAE bolts. And of course, American made aircraft are non metric, from the lowly Cessna 150 to the Mighty Gulfstream G800.

 

[Jordan_FX4]

In agriculture and especially the grain handling industry SAE is still the predominant fastener. Even new construction grain conveyors and equipment are 100% SAE fasteners, mostly 9/16 and 3/4” head bolts. It’s the opposite of the automotive world, but we keep very few metric sockets and wrenches in our shops and order 9/16” impact sockets in bulk.

 

[04silverado6.0]

My mustang dyno uses sae fasteners. Sometimes that 9/16 will fit better than the 14mm especially on cheap chinese bolts.

 

[eljefino]

The building trades are nearly completely SAE (or should I write "inches" as the Society of Automotive Engineers doesn't enforce lag bolt standards.)

 

[D60]

Fractional is still present on plenty of stuff, esp here where vehicles don't rust. Ford Windsors, Chevy 350s and Dodge Magnums may be fractional in many areas because it's legacy.

As noted SxSs, mowers, etc may still be fractional.

Furthermore for things like spring eyes and shock eyes I'll often substitute a 9/16" bolt in place of 14mm.

Try running a Bridgeport with only metric. The drawbar is 7/16-20. 1-2-3 blocks are tapped 3/8-16. 2-4-6 blocks are tapped 5/8-11. Toe clamps use a 5/8 T-slot and are tapped 1/2-13. AFAIK everything on a Kurt machine vise is fractional.

Trailer ball shanks are all fractional.

Then you've got oddball stuff like mic stands that use 5/8-27 and Harley neck stems are..... 1"‐27?? is it?

I realize this is an automotive-centric forum, but there's a whole world out there of mechanical equipment. We tend to get a little myopic and think anything not in our direct line of sight must not exist.

Everyone should stock tools as they see fit but fractional won't vanish from my life anytime soon. I'd feel handicapped without it, like owning a welder without a single grinder or a mill without a lathe.

 

[SC Maintenance]

I miss fractional wrenches, but almost never use them. I have such a surplus I put them in a separate box under the bench.

Automotive went metric in the 80's, but as mentioned a lot of ag and other stuff is not.

My problem is anything you build is fractional because metric hardware is way too expensive. So my Chonda generator for example is metric with fractional bolts holding the wheels that I added later on

 

[ajchien]

Rebuilt two swimming pool pump motors a month ago. 1/4, 5/16, 7/16, and 1/2 were used a bunch.

 

[daniel327]

I've got sockets and wrenches (aka spanners where I'm from) that fit both metric, standard and other fasteners.

The heads look like this:

They're useful for all of these fastener head shapes:

 

[hrv]

I have a Metrinch tool set that I got in the 80s and still use today...It works on both....

 

[Trav]

I only have a few small sets of SAE sockets and wrenches, I don't have much use at all for them anymore. When I first started 54 years ago there were only a few metric and Whitworth (BSW) cars that were common in the USA. The last time I used SAE was on the old Ariens snowblower. BSW is long gone except for a few antique English cars and bikes, I kept the tools just in case I find another old car or bike that needs repair but they are dusty. Time to put SAE in the same dustbin of history IMO.

 

[ka9mnx]

I use both but SAE more so.

 

[PontiacHO]

Of course my 1968 Pontiac is all SAE. Trying to save a few bucks, I purchased a Harbor Freight SAE tap and dye set. This was a joke. I chased threads during my engine reassembly and found that this tap cut threads that weren’t SAE but not Metric. I reckon there is a Harbor Freight thread count-pitch that I wasn’t aware of. They have yet to offer nuts and bolts to correspond with their taps/dyes. Yes I was frustrated…..

 

[FowVay]

SAE was used in countries that hadn't adopted the metric system. I can remember when Ford couldn't decide whether they wanted a metric car or a Imperial car so they just used both. Drove me nuts to need two sets of wrenches to change a alternator.

Fastforward to the 21st century and you should probably stock your toolbox with the cool assortment of metric doodads. I did replace all of the toilet seats in my home today and the new seats used a neat fastener that applied the correct torque to the bolt and then snapped the head of the nut off. I had to dig down in my tool box to find a 5/8" box end wrench for this task.

Based on this information, if you're working on the Space Shuttle, buy Metric. If you're installing toilet seats, buy SAE.

 

[Cherrybomb]

My mustang dyno uses sae fasteners. Sometimes that 9/16 will fit better than the 14mm especially on cheap chinese bolts.

Yes!Always use the wrench or socket that fits the best,don't worry about the marking

 

[supton]

I have a limited set of both, but usually use metric, as most of my stuff is imported.

At work they have more or less stopped designing mechanic items with SAE. I'm for it, but then I wind up with strange dimensions... that are nice round numbers in inches. Someone wants a PCB designed that is 50.8 x 101.6 mm? Connectors and IC's are slowly getting there, but 2.54 mm is very common dimension, or some nice fraction of that.

 

[Kestas]

The aircraft programs I've been involved with all use SAE.