My ex-wife was a variable nut driver
Variabble nut drivers are dangerous on the road and should be curbed.
Google Universal Nut Driver
Just get a straight socket driver and use your sockets.
Welcome to a world with tools that you need once every three or four years.
That being said, they're bigger than most of the little sockets you may need, be careful with torque. And a small metric set of sockets isn't that expensive these days.
There’s this kind of thing:
https://www.google.com/search?q=universal+socket
I can’t speak to whether it’s any good or not and I probably would never buy one, but they exist.
Yes, there are several styles that exist, none quite as good as a driver meant for your particular nut or bolt, so I recommend “nutting it up” (lol - make myself laugh) and buying a proper set.
If you do want to go the variable route - and I understand why — the suggestion to find a “variable nut driver” is the route to go.
I have an old British defender with a random mix of Imperial and metric parts, so I understand. Happens in the oilfield a lot, too. The Russians even have some weird third set of measurements.
A guy who doesn’t want a bunch of tools laying around?
No such thing aside from Vise-Grips.
7mm is 7mm
8mm is nearly the same as 5/16
9mm - never seen that size used
10mm is slightly bigger than 3/8
11mm is same as 7/16
12mm is 12mm
13mm slightly bigger than 1/2
14mm slightly smaller than 9/16
16mm and 5/8 the same
17mm and 11/16 kinda close
18mm is 18mm
19mm kinda close to 3/4
So 7mm, 12mm and 18mm have zero crossover possibility
8mm, 11mm, 16mm are matches to ASE sizes
The rest depend on things like how tight the bolt/nut is.
If you have a Harbor Freight near you, they have socket sets cheap. They currently have a 10-piece, 3/8” drive deep-socket set in either SAE or Metric for $10, or a 21-piece 1/2” drive combo SAE and Metric (with ratchet) for $24.99. You’d need to grab the coupons for each on their website.
I find their tools to be pretty good, especially for occasional use. I wouldn’t buy them if my job depended on daily use.
Just about any parts store has metric sockets you can purchase individually (I’d strongly recommend 6-points). Plus they’ll have several price points of sets. Ditto with Lowes carrying Craftsman tools. I’d guess Home Depot too. Even Walmart probably has a cheap metric socket set. And there’s always Harbor Freight.
Consider the time involved if you round off that fastener and then need to, best case, buy a set of vice grip pliers, or worse case drill a hole in it and buy a set of bolt extractors or, if a nut, cut or chisel it off.
Perhaps that is why you don't have the right tool on hand when you need it.
You can’t slip out of this, you will have to buy a metric set, the good news is that you will be using it the rest of your life, it is common.
You only need a few for 80% of the work.
Just break the piggy bank and buy them.
Save yourself the headaches.
You just need one socket set that has SAE and metric sockets. I must have half a dozen sets like that, but you can get by with just one if you rarely use them. Don’t try to use SAE near-equivalents and don’t use those one-size-fits-all jokes of a socket. American vehicles have been all metric for decades now. And all that junk that comes from China and other countries is all metric. I use my metric sockets and wrenches way more than I use my SAE tools.
