Commonly used metric sizes above 19mm?

[3 at 8]

I have an 11pc metric combination wrench set sized from 6mm – 19mm; excluding 11mm, 16mm and 18mm. I have a pouch to store them in with 14 spaces. To satisfy the requirements of my OCD what sizes would be most useful to obtain to fill the remaining 3 pouch slots between the omitted sizes mentioned and any sized above 19mm. I am a hobbyist and these are for spares so can’t say anything specifically they’d be used for as for now. Sorry the questions kind of vague. Also; how often if ever do you encounter 11mm, 16mm or 18mm as these seem to be commonly skipped sizes in some sets? Thanks.

 

[Jaralaccs]

21,22,24

from an automotive perspective
11 and 16 are used but rarely, don't remember that last time I used 18

 

[McRae]

21, 22 & 24. 16 & 18 is getting more common as most european car manufacturers has switched from DIN to ISO standard, i.e an M12 bolt has now an 18mm head instead of 19mm in order to save on steel costs.

 

[RKA]

I've used 16 and 18 doing suspension work on all 3 of my past Audi's. Above 18, I'd say 21, 22, 24. I have a 1/2" impact set and everytime I've needed something beyond 19, those sockets have worked fine with plenty of clearance. I don't think I've got a single chrome 3/8's beyond 19mm.

 

[bart1]

Some that I can think of on my stuff:

27mm service wrench for setting pulley tension
24mm for tie rods
32 & 36mm axle nuts
21 & 22mm top strut nut
24mm fan nut

 

[RKA]

I've used 16 and 18 doing suspension work on all 3 of my past Audi's. Above 18, I'd say 21, 22, 24. I have a 1/2" impact set and everytime I've needed something beyond 19, those sockets have worked fine with plenty of clearance. I don't think I've got a single chrome 3/8's beyond 19mm.

Doh! Scratch all that...for some reason my brain wasn't reading combination wrenches and I was thinking 3/8" sockets. Bart's list is good, but I won't touch a tie rod or axle nut with a combo wrench!

 

[bart1]

No, you have to use a socket on the axles.

 

[Singlecut]

Definitely have a 21 mm. Above that, I myself haven't ran into anything bigger in metric land. I did watch some youtube videos with some guys working on tie rods on a Dodge (I think) and they used a 26 or 32 or something...I dunno if you wanna tackle that.

Which reminds me, when I saw your name, I dunno why, but I immediately thought of this:

 

[franzdom]

Scratch again, you must use an open end on the adjustment and inner sides of tie-rods, so yes combo wrenches are needed. For BMW the tie-rod locknut is 24mm and the inner is tightened with 34mm. No sockets here. Anyway, 16 & 18mm are definitely getting more common. If you want to skip with the 11mm and put in 16 & 18mm then go larger, 21mm is nice to have as 22mm can almost always use a 7/8" if necessary. My OCD has x-19mm then 21mm, 22mm, 24mm, 27mm, 30mm, 32mm...20, 23, 25, 26 are extremely rare.

 

[Rossco]

21, 22, 24, 27, 30, 32

Sets tend to Include 23, 25, 26, 28, 29 .. Useless

 

[Gary S]

There are NO commonly used metric tools in my garage. My metric tools are seldom used. I own old Chevys that need my SAE tools. My lawn mower, snow blower, and rototiller are all still SAE too.

 

[plinker]

On my '89 ranger, I've used 10-19 plus 21, & 24

11mm (hex) is a size Ford uses on headlights and some under the dash things I've found.

 

[Mr.Nutcase]

Also; how often if ever do you encounter 11mm, 16mm or 18mm as these seem to be commonly skipped sizes in some sets? Thanks.

I have seen them on Fords, GM,

 

[petee_c]

11mm was needed for the bleed screws on VW and probably Porsches. I didn't have a long one when I did my brake bleed.

Now I do, I just got a 30 piece SAE/metric wrench set...

oh yeah,, u were talking sockets...

Most of the stuff I do is below 19mm in size.... Common is a relative term in general automotive shade tree mechanic type jobs if larger than 19mm.

 

[Toolhorder]

There are NO commonly used metric tools in my garage. My metric tools are seldom used. I own old Chevys that need my SAE tools. My lawn mower, snow blower, and rototiller are all still SAE too.

Helpful post...

 

[greasemonkey44]

I use 18 fairly frequently; the updated bolts on 2500 and 1500 chevy rear calipers are 18 and although you can use a ratchet and socket its tight
the 11 ive used on some bleeder bolt or a hyd line
16 is fairly rare, but itll show up the minute you dont have one

honestly when it gets bigger than that i use a ratchet and socket or impact

 

[Cryts]

16mm - European cars
18mm - Euros, and I use 18mm sockets pretty regularly on some Ford/GM/Chrysler front ends
20mm - only thing I can think of would be the fittings on Grand Cherokee ps pressure hoses
21mm - half the tie rod jam nuts out there
22mm - another 40% of jam nuts
23mm - tie rod jam nuts on some Envoys/Trailblazers (others are 22mm)
24mm - common enough... Like rear toe cams on certain late-model Hondas
25mm - can double as a 1" for rear toe turnbuckles on W-bodies
26mm - inner tie rod end on Envoys/Trailblazers
27mm - Toyota and Kia front end cams

 

[Moose-LandTran]

Commonly used sizes above 19mm are 21, 22, 24, 27, 30, 32, 36mm.

My sets cover 4-46mm, and 65mm. I used them all, aside from a few sizes that don't exist in the real world. (31, 37,38,39,40, etc.)

Even weird sizes like 41mm and 52mm have their place.

 

[greasemonkey44]

speaking of wierd sizes; ive got a 35 torx i dont think ive ever used it, anyone else ever used one?

 

[Moose-LandTran]

speaking of wierd sizes; ive got a 35 torx i dont think ive ever used it, anyone else ever used one?

My friend has one in a cheap 1/4" bit set. I don't know of a T35 existing though.



With these sizes, it depends on what you work on. I work on anything that comes in the shop, 99% of which is metric so between all the brands and countries of origin, everything gets used.

 

[bimmer630]

20mm Is on GM fuel filters too. I finally had to buy a 20 recently. also some GM rear disc brakes require a 20.

Ive never seen a 23 or 25mm fastener, but for some reason my gearwrench set came with a 25mm
-You need the real big stuff, 32, 36, etc for most fan nuts
-11mm Is on alot of BMW engine stuff
16/18- BMW and other Euro imports are full of them
Actually, I worked for BMW for 10 years and the only time I pulled out a 14mm was for X5 rear exhaust bolts.
Its weird how a common size with a company like GM or Toyota(14mm) is almost nonexistent on a Bimmer

 

[3 at 8]

Thanks for all the fast replies. I think I have a 20 somewere, so 21,22, and 24 is they way I'll go.

 

[3 at 8]

Which reminds me, when I saw your name, I dunno why, but I immediately thought of this:

I'ts a reference to the fact that I seem to allways have three shells left at station number eight in ***** shooting.

 

[Moose-LandTran]

20mm Is on GM fuel filters too. I finally had to buy a 20 recently. also some GM rear disc brakes require a 20.

Some Jaguar fuel filters use a 20mm banjo bolt.

Ive never seen a 23 or 25mm fastener

Mazda 6 front lower control arm ball joint nuts are 23mm. I've used 23mm before for something else, but don't remember what.

-11mm Is on alot of BMW engine stuff

On newer engines too? Someone said that before, but i've only used 11mm on BMWs for brake/clutch lines and bleed screws.

Its weird how a common size with a company like GM or Toyota(14mm) is almost nonexistent on a Bimmer

It's to do with industrial standard for bolt thread and hex size. JIS and DIN standards. M10 DIN is 16mm, M10 JIS is 17mm.

 

[Rossco]

Well all metric is derived from imperial .. So larger sizes most of the time coincide.

19mm = 3/4
20.6mm = 13/16
22mm = 7/8
38mm = 1 1/2
41mm = 1 5/8 etc etc ..

The only time I use a 23mm is to extend a wrench ..

Caterpillar is moving over to Metric, But they do things different and put a 16mm head onto a 10mm bolt instead of 17mm ... Its all about buying our bolts I supose.

 

[MattT]

Even weird sizes like 41mm and 52mm have their place.

41mm is used by Honda on 4 wheelers and when I was searching for 41mm tools the search turned up one automotive wrench. Was for a fan clutch IIRC. Also FWIW 1 5/8" is only 0.011" bigger than 41mm which is close enough and a lot cheaper and easier to find. SAE will work for a lot of larger metric.

 

[z28snksknr]

My O2 sensors are 22mm. I do not have a 22mm wrench and I'm currently replacing my O2 sensors. FML.

 

[Moose-LandTran]

Well all metric is derived from imperial .. So larger sizes most of the time coincide.

It's all co-incidence. Napoleon didn't use the Imperial system as a base!

41mm is used by Honda on 4 wheelers and when I was searching for 41mm tools the search turned up one automotive wrench. Was for a fan clutch IIRC.

It's not something i use often, but i do have a 41mm wrench. So far used for the extension joint nuts on Mercredes-Benz driveshafts and for VM-System diesel engine crank bolts. (Used it to turn the crank during head gasket job.)

My O2 sensors are 22mm. I do not have a 22mm wrench and I'm currently replacing my O2 sensors. FML.

Get a dedicated O2 sensor crowfoot, like the Blue-Point ones, or you'll be even more upset when the wrench spreads and slips.

 

[MrMark]

20mm Is on GM fuel filters too. I finally had to buy a 20 recently. also some GM rear disc brakes require a 20.

Ive never seen a 23 or 25mm fastener, but for some reason my gearwrench set came with a 25mm
-You need the real big stuff, 32, 36, etc for most fan nuts
-11mm Is on alot of BMW engine stuff
16/18- BMW and other Euro imports are full of them
Actually, I worked for BMW for 10 years and the only time I pulled out a 14mm was for X5 rear exhaust bolts.
Its weird how a common size with a company like GM or Toyota(14mm) is almost nonexistent on a Bimmer

Yeah, I was surprised to find MB bleeder screws were 11mm. I never had used that size before. I seem to recall a few 18mm on something Mercedes. I did buy a 20mm for something suspension related on a Corvette, so it is used.

 

[Rossco]

It's all co-incidence. Napoleon didn't use the Imperial system as a base!

Is this before or After Joseph Whitworth devised a standard for screw threads?

 

[earlthegoat2]

Of all sockets over 19mm, I use 22mm the most often.

 

[Singlecut]

My O2 sensors are 22mm. I do not have a 22mm wrench and I'm currently replacing my O2 sensors. FML.

As posted above, 22mm is 7/8.
I know you have a 7/8 in your garage.

 

[cosmik binturong]

As posted above, 22mm is 7/8.
I know you have a 7/8 in your garage.

or he could use his metric adjustable wrench if he has one...



a bit of SI history there.

 

[speed bump]

My O2 sensors are 22mm. I do not have a 22mm wrench and I'm currently replacing my O2 sensors. FML.

So buy a cheap 7/8" 02 sensor socket the difference isn't big enough to really notice. Either that or cut the pigtail off of the old one, use a socket to remove, and reinstall with a crescent.

 

[matthew]

Well all metric is derived from imperial

Nope, they started out completely separately, but nowadays the inches are actually defined in terms of millimeters... the internationally accepted definition of 1 inch is 25.40mm.


I've used 11mm quite a few times on brake bleeders. It's very close to 7/16" if you have to substitute, but I'd say 11mm is still good to have. I used 18mm and 21mm last weekend on suspension arms on an old GM. And I've used 16mm on drain plugs before, although you can get by with a 5/8".

 

[Bran Diezel]

i use 20 and 23 all the time...


on swollen caps on 3/4 and 7/8 lug nuts

 

[franzdom]

i use 20 and 23 all the time...


on swollen caps on 3/4 and 7/8 lug nuts

This thread was about wrenches

 

[granitestater]

The lower bolts on the rear shocks on my 2000 Ford Expedition are 18mm

 

[franzdom]

The lower bolts on the rear shocks on my 2000 Ford Expedition are 18mm

Same for my e46

 

[tonydanzah]

cadillac cts use a 22 or 23 on the tie rod locking nut