Why 20mm???

[HubbaBubba]

Saw a post for a 20mm wrench and was thinking....why?
I have never seen or come across a 20mm nut.

Please prove me wrong and tell me about why a 20mm socket or wrench is needed (other than having a full set) in the REAL world.

Here we go...

 

[vssykes]

gm fuel filters

 

[Stick]

20mm wrench is needed for line nuts on GM fuel filters.

I've used 20mm sockets on heavy equipment fasteners before.

 

[andrew_94]

...might be making myself look silly, but my metric wrenches go up to 19mm. i tried to change the flapper valve in the toilet and 19mm was too small

 

[yogitech]

Power steering lines on Ford diesel gearbox...

 

[greasemonkey44]

in the last week a gm fuel filter; ended up using an adjustable on it and turning the nut with the right flare nut wrench

 

[Fedwrench]

In addition to GM fuel filters, the AC fitting where the orifice tube goes on some GM trucks is also 20mm. I have never used a 20 mm socket though. You could also ask the same question about 23 and 25mm too. Most tool makers offer a topper set consisting of 20 to 24mm. I could never justify the 23mm wrench. I guess it's like those Hansen socket racks, some prople just hate to skip sizes.

 

[malibu101]

FWIW- I have a 20 that's seen some use although I don't know exactly what it was used on. I also bought a 22 at some point in time that I used for something too.
I don't have a 21 or anything over the 22 and guess I never needed any.

 

[Macneil]

FWIW- I have a 20 that's seen some use although I don't know exactly what it was used on. I also bought a 22 at some point in time that I used for something too.
I don't have a 21 or anything over the 22 and guess I never needed any.

Pitman arm retainer nut on Jeep steering boxes are 22mm.

I have a 20mm socket and open end wrench and they show some wear but like another said, I haven't the slightest clue as to what I personally would have used them on!

 

[kar650]

Capri axle nut is 20mm?

 

[BerninicaCO3]

I'd swear that the oil filter wrench for newer volvos, requires in turn a 20mm socket to turn the larger filter wrench.

I used to think the same thing about 18mm a couple months ago. There's always *something* that will take that oddball size.

 

[kar650]

I used a 20mm impact to get off older GM chorme caped lugs inpregnated with rust

 

[luvit]

Capri axle nut is 20mm?

ugh, i'm wrong, 30mm axle nut, 22mm lug nut.
.

 

[djb2]

BMWs use 22mm on the M14 subframe fasteners and a few other locations. Asian cars tend to use 23mm and sometimes 21mm.

 

[williaty]

Because sometimes 21mm nuts rust.

 

[Seanbev24]

BMWs use 22mm on the M14 subframe fasteners and a few other locations. Asian cars tend to use 23mm and sometimes 21mm.

The only 23mm I've ever used was a socket for the lower ball joints on a newer Mazda 6

 

[Lippyp]

I've used 23mm sockets on things like hub nuts on my Trooper.

 

[coldfusion21]

I swear a Volvo 240 uses a 20mm nut on the front suspension, could be wrong though.

Definitely not a common fastener size.

 

[MattPersman]

20mm are on DR 1500 ram truck power steering lines

 

[wheats71]

20 mm wrench also needed to hold brake caliper guide pins from spinning when removing
caliper bolt on 07 and newer trucks

 

[eyeboltman]

Good call Guys ....I hve used american for years now at my new job it's metic . don't think I used a 20 mm have use 18 ,19 ,22, 24 ,27,30, 36 .46 mm
on bolt and nuts all the time . 9 mm 1-2 time and all so used all the small ones these are on steel rolling machines . THE 18 mm is now fitting on the 12 mm thread nuts that used to be 19 mm now I dig in the new box of nuts 300-500 just to find the 19 mm? I read so place that this is done over seas as a cost saving ? and it OK .The bolts still see to be the same size The 28-29 mm ,20 years old in the box still looks new !!! I see that the car guys used different wrenches that I use in building machines and we have more room to work in them , not like a BMW or MB .. Thanks guys

 

[hhuytho]

in the last week a gm fuel filter; ended up using an adjustable on it and turning the nut with the right flare nut wrench

I did the same thing last week, an adjust table wrench for the filter nut and a flare nut wrench for the line. It worked fine. I'm hunting for a 20mm wrench though...

 

[SuperSocket]

Google image search "20mm wrench" and you will get lots of uses for them

 

[osborn.ozzy]

19mm, 21mm, 22mm is used all the time for lugnuts

 

[chevelle67]

I'm just speculating but I would guess they would be useful on 20mm fasteners......sorry couldn't resist.

 

[Jim C.]

In a pinch, 25/32" = 20mm.

 

[eyeboltman]

In a pinch, 25/32" = 20mm.

Jim thanks for the update .I got a wrench from a friend. it's 1 and 31/32 what's that for I have seen the 25/32 and 19/32 but 31/32 it's a Williams ? Thanks

 

[cotjocky]

I know this thread is a couple months old, but...

I changed the radiator in my 1997 Chevy 3500. It has 2 oil cooler lines that go in to the drivers side of the radiator. Those two lines require a 20mm line wrench. Luckily I was able to break it loose with a 20mm open end wrench. My snap on line wrench skips 20mm (19mm-21mm). :-(

 

[FergusonTO35]

In my experience, a 20mm is just what you need for a 21mm or 13/16 lug nut that has lost its chrome cap, is rounded but still hex shaped, or is undersize from the factory. Some of your older Toyota one ton trucks use a 23mm lug nut. At the first dealership I worked for the parts delivery truck used 23's.

 

[Notwerk]

Slightly off topic, but has anyone ever generated a list of wrench/socket sizes and common uses for them? Might be a heavy list, but it would be cool to see which sizes have odd uses, etc.

 

[BajaBound]

I use 20 and above all over my Ram 2500

 

[Moose-LandTran]

I have a Jeep Grand Cherokee ******* me off right now with 20mm fittings on the power steering lines.

And WTF kind of an idiot designs a cooling fan that's run off the power steering system?

 

[honcho]

A bit off the 20mm topic, but related.

I know designers and engineers pull things out of the parts bins to use in their creations and manufacturers purchase sub-assemblies from other companies to integrate into their products but it sure would be nice if they would engineer their products to use a minimum number of faster types and sizes.

Recently, I changed the shocks on my Ford F250 and I was surprised by how many different size hex wrenches / sockets I had to pull out. If I remember correctly I used three different sizes on two separate bolt/nuts for the rear shock. I don't think there's any reason they couldn't have used one size for all the bolts and nuts.

Before the program was killed by the Defense Department, the Commanche Helicopter project touted that all unit level maintenance could be performed using a small toolbox with about 10-15 different handtools. Aviation techs will probably roll their eyes at that claim but designing equipment that will require maintenance and repair to use a minimum of different tools and hopefully no special tools would be appreciated by the folks that have to repair the equipment.

 

[bgott]

And WTF kind of an idiot designs a cooling fan that's run off the power steering system?

Lexus.

And Lincoln used to use power steering pumps that bolted onto the end of the crankshaft. Then they quit making parts for it so you had to adapt a regular P/S pump onto the engine. Plus they used to drive the wipers off of the P/S pump. I bet they did it so they could feel sophisticated.

 

[tbobbo]

My 20 mm stuff is not really used all that much, but i use ot once a week. My 23 mm socket is used everyday. Fits the best on alot of new dodge lugnuts, 1/2 pickups mostly.

 

[jvitez]

Wrenches on lugnuts? Why scrape knuckles when I can use a long handled ratchet? I've never used a wrench for lugnuts.

And, AFAIR I've never used a 20mm anything. Larger sizes on my Dodge 3500, yes.

 

[greasemonkey44]

I have a Jeep Grand Cherokee ******* me off right now with 20mm fittings on the power steering lines.

And WTF kind of an idiot designs a cooling fan that's run off the power steering system?

automotive engineers, heard of it on a lexus....never seen it
its a cool idea; spins up with the engine; spins down with the engine
terrible execution
theres a reason everyone; even 1/2 ton trucks are changing over to electric fans

 

[Moose-LandTran]

automotive engineers, heard of it on a lexus....never seen it
its a cool idea; spins up with the engine; spins down with the engine
terrible execution

But that's exactly how a viscous fan works!

 

[MattPersman]

i gotta tell you I have no idea why they made the hydraulic steering/fan setup. it was pretty reliable however. expensive when it does fail

 

[Moose-LandTran]

i gotta tell you I have no idea why they made the hydraulic steering/fan setup. it was pretty reliable however. expensive when it does fail

Worst radiator i've ever changed.