Metric Talk: Most uncommon size

[Tony N.]

I have a couple socket sets/wrenches and I notice the following sizes are usually skipped:

25,28,29

Anyone working on foreign cars who encounter these sizes? I'm wondering if I should buy them separately.

Post your experience and let us know which size are most uncommon for you.

 

[garboui]

I've encountered both 25's and 28 for tie rod jam nuts with jap cars.

 

[greasemonkey44]

I have a couple socket sets/wrenches and I notice the following sizes are usually skipped:

25,28,29

Anyone working on foreign cars who encounter these sizes? I'm wondering if I should buy them separately.

Post your experience and let us know which size are most uncommon for you.

9mm
seen most everything else; but ive also not need much stuff bigger than 22

 

[jamesc]

i have never needed a 28 mm before and most 25 mm I usually think is 1", and over 1" I assume everything is standard and start using stanard sockets and wrenches I don't know why I do this.

9mm is used on alot of euro brake bleeders. newer ford escapes have 9 mm hex on the brake caliper, alot of hex bit sets don't have 9 mm in them.

20 mm is pretty uncommon I can only think of gm fuel filters that use that size.

23 mm is really uncommon I really only use it on rust swollen 22 mm jam nuts.

 

[purplezr2]

9mm for audi/vw slave bleed and pressure plate bolt also

 

[wreckerman5357]

I have never ran into 20mm.

 

[Peoria Man]

Have never needed a 9mm. Never even owned a 9mm socket until I found a new-looking Craftsman in a junkyard - what are the odds? I sometimes wonder if the previous owner ever misses it.

Needed a 12mm for just about the first time recently to remove the electric power-assist motor on a GM car. Can't recall ever needing a 12 before that.

Hmmm... 7, 8, 10, 13, 14, 15, 18, 19, 21...uhhh 24mm maybe. Haven't ever used an 11, 16 or 17 that I can think of.

 

[LincolnCont.]

I have only seen a 28 or 29 mm combo in one application at work, on the drive motor mounting bolts for a Hagglund Hyd Pump. Need it about once a year at most. After 10yrs of employment working around quite a bit of forgein equip I foolishly thought I should spend some bucks and buy 20,21,22,23 combo's...just in case. 2.5yrs later and still never been used. lol

 

[NC-Fordguy]

11 mm fits the thermostat housing bolts on edlelbrock aluminum intakes for Ford windsor series engines.

I hate having these two oddball bolts on my bronco. If I ever pull the intake I will drill those out and replace them with a standard size

 

[davesnothere]

7, 9, and 11 are the 3 I use the least. And anything smaller than 7. And above 24 I only use 27, 30, 32, and 36 regularly.

 

[Super Sport]

7, 9, and 11 are the 3 I use the least. And anything smaller than 7. And above 24 I only use 27, 30, 32, and 36 regularly.

I use 7 quite often on GM interior parts.

 

[davesnothere]

I use 7 quite often on GM interior parts.

Forgot about those. Only thing I could think of using 7 on was ford coils.

 

[mtkst19]

23, 25, 26, 28, 29 are the sizes i seldom use. 5-24 with exception of 23 i use all the time. 27 i run into on axles and harmonic balancers. 30, 32, 34, 35, 36 axle bolts. of course, now i run into a lot of 12 point in those sizes too. 46mm socket gets used on some bmws. then toss in torx, torx plus, triple square, allen,5 lobe torx, e torx, and tamper proof versions where applicable. as soon as i think i might be done buying hard tools some oem comesout w/ a new fastener tha i need to "tool up" to deal with.

 

[JASTECH]

Below 7 I used the 4.5 on GM seperate coils, think it was on Z24? That's hard on my memory, lol.. Used to work on Ply. Champs abit then a Yogo once in a import moon.
I try not to work on Jappys anymore unless I have too. Now on some tractors the bigger 22+ come in play.

 

[Wrench 2201]

I've used a 20mm on the tie rod jamb nuts on some Audis and also on one of the line nuts for the fluid driven fans on Grand Cherokees. And of course on the Gm fuel filters. The Jeeps made me buy a SO flare/crowfoot wrench, only time I ever use it.

 

[supersteve]

23.
I don't think I have ever used a 23mm for anything, ever.

I did use a 20 for a jamnut on a strutrod on a Jap car ages ago.

You need a 9mm deep socket for the power valve on the floor of the float bowl on an old Toyota (Aisin?) carburetor.

 

[wafrederick]

17mm is used on most asian cars such as Hondas,Toyotas,Nissans,Mitubishi.Kia,Hyundia,Daewoo use 17mm too.20mm is used on high pressure power steering lines for 2002 and up Dodge fullsize trucks.I have one 6 inch 1/4 hex socket for crank sensors in Dodge trucks with the 3.9,318 and 360.A conventail 1/4 hex socket won't reach the bolts holding down the crank sensor if there is an EGR tube in the way,the crank sensor is behind the passenger side cylinder head.

 

[geologist]

9mm
seen most everything else; but ive also not need much stuff bigger than 22

Mitsubishi Eclipses - rod bolts and some other stuff on the 90-98s

 

[spongerich]

Definitely depends on what kinds of things you work on.

I mostly work on Japanese bikes and ATV's, so I use 8,9,10,12,14, and 17 all the time.

I've never used my 13 or 15 as far as I can remember.

IIRC, GM autos are full of 13's

 

[Jawn]

IIRC, GM autos are full of 13's

10, 13, and 15 will do a lot on GMs. I have heard some say 18mm is another oddball, some of the control arm pivot bolts (IIRC) on my old J-body were 18mm.

As to "UN-common"... I don't recall using much in the way of 7mm.

 

[bsaint]

1.27mm socket heads for a small motor.

 

[jjjrmx5]

If you work on enough things in life, you will likely encounter almost every sized fastenr head available.

And why I say that is there is no exact SET standardized rule as to what one sized head goes with what sized fastener, but more a a range of head sizes to fit each thread size and pitch (and then there are variations on that for specialty fasteners).

e.g.---A metric M8x1.25 bolt may use a 11mm or 13mm head on a Toyota, but a 12mm when when spec'd on a GM product. It's all about what is availabe, who spec'd it and what is the application.

It can change from car to car and from mfgr to mfgr.

As someone who has stripped 2 (or more on certain days) brand new cars/vans/suv's down to rolling chassis' a day with a team, ya just never know what they put in there. The bolt size and pitch is constant, but the head sizes do gets wonk. BTDT first hand.

 

[osborn.ozzy]

never used a 9mm but I use a 7mm on some hose clamps and had to use a 20mm impact socket the other day because bobby joe used a 21mm socket on his 19mm lug nuts

 

[jjjrmx5]

never used a 9mm but I use a 7mm on some hose clamps and had to use a 20mm impact socket the other day because bobby joe used a 21mm socket on his 19mm lug nuts

LOL.

I have a neighbor that used to own a Ponitac Vibe that had the lug nuts with teh chrome 2 piece nuts with the fancy acorn nut chrome cap cover pinched over std. nuts.

Garage she took it to ripped two of teh nuts to bits with an impact when intalling as they were 21mm new, but with the little acorn cap ripped to shreds and then pried off they were 20mm when she needed a flat tire changed (I'm a helpful neighbor) .

One of those instances of needing those odd sized tools.

 

[Tunger]

9, 11, and 20 are the LEAST used in my box. 9 I use on occasion, usually when installing trailer harnesses as some of the plug brackets come with 9mm head fasteners. 11mm for steering shaft pinch bolts on GM, and 20mm I've only ever used on gm fuel filters. I used to use 5.5mm all the time doing hvac work on gm stuff.

 

[Xavis00]

I can't remember ever using a 16, 17, or 20.
And 9mm is used on Ford Ranger rear door glass and rear windows.

 

[plinker]

I use a 7mm fairly often as the shop stock's 4mm hex bolts, For some reason Fastenal set the bolt bin with them. Handy none the less. I've also seen hose clamps with them.


Except for a 25 & 26, I have used 7mm to 32mm at least once or know of a specfic use for the wrench.

 

[Justin1776]

Volvo XC60 brakes caliper bolts are 9mm hex screws

 

[Peoria Man]

I used to use 5.5mm all the time doing hvac work on gm stuff.

Yep, they're all over and inside GM dashboards, and under the hood to attach the distributor cap, ignition module and DIS coils. A nutdriver is handy for most of them.

 

[kippieland]

I find it funny that if you get a MM set of Craftsman wrenches you get an 18 but no 17. If you get a Taiwan set they all have the 17 but no 18. I have never used an 18 but use a 17 all the time on my subaru. I have one 11 mm both but never used a 9, 13, 15, or a 16. My Yamaha MX bike is a 6, 8, 10, 12, 14, 17, 19, 22, 27, 32 for the whole bike.

 

[zjrog]

28mm for the bolts holding radius arms to the TTB setup on Ford Rangers and Explorers.

 

[shoturtle]

allot of socket sets skip 15 and 16 allot of times.

 

[SliderXTM]

I definitely used the complete range from 7mm to 21mm for cars and bikes from Japan, France, Germany and the former states from behind the iron curtain, except 20mm.

 

[lbulloc2]

e.g.---A metric M8x1.25 bolt may use a 11mm or 13mm head on a Toyota, but a 12mm when when spec'd on a GM product. It's all about what is availabe, who spec'd it and what is the application.

I think you have those mixed up - Toyota use 10mm for m6x1 fasteners, 12mm for m8x1.25, 14mm for m10x1.25, 17mm for m12x1.25, 22mm for m14x1.5 bolts and 24mm for the nuts

Working in the UK I see most metric sizes, most common everyday use ones being 8, 10, 12, 13, 14, 17, 19, 21, 22, 24, 27, 30, 32, 36, 41,

7 is used on most hose clips and m4x0.75 bolts, 9 is common to VW and BMW brake *******, 11 is another bleed ****** size, 15 and 18 are used on most FoMoCo and former owned brands such as Jaguar/Land Rover and ford itself, 16 is common on VW, 20 I use rarely but is found on some aftermarket damper struts, 26 is found on DAF (Paccar) semi truck axles, 33 is a common semi truck wheel nut size, 38 and 39 seem to be becoming common on drive shafts, 54 is Toyota Land Cruiser axle end nut size.

Sizes I've never used but own just in case are 23, 25, 28, 29, and if they do come out of my box it's mostly for hydraulic line work, which are probably SAE anyway

I don't think 31 exists by the way, and while I have seen a 35mm socket I have no idea what it's used for

 

[Carson_13]

The only size i dont remember using from 4.5mm to 24mm is 23. I have it but dont remember where it came from its a random non match to my sets. first post creeping for years finally made an account haha.

 

[tronvex]

I notice when purchasing or looking on purchasing new socket set that every manufacture skips the 23mm. I only use it on my S2k differential fill plug. To find one was a pain, haven't found any use for it after that.

 

[Moose-LandTran]

I have a couple socket sets/wrenches and I notice the following sizes are usually skipped:

25,28,29

Anyone working on foreign cars who encounter these sizes? I'm wondering if I should buy them separately.

25 for various things.
28 for diesel injectors.
29 for diesel injectors and fan switches.

 

[Hawk321]

Also funny and a fact is...the manufactors (cars) use/change the head size of a fastener to an uncommon size...example
Volkswagen...

First all standard sizes like 13 and 17 mm today everything is mixed mostly 16 + 18 mm also many 12mm fasteners.

 

[tjmonsen5]

the craftsman ratcheting wrenches go up to 18, which i have never used before. I wish it skipped 18 and had a 19 because I use it on the suspension of my bmw.

10, 12,13, 15, 17, 19, 22 are used all the time on my cars.
10mm, 8mm hex key, and 17mm are the only sized bolts on my jetski

 

[Moose-LandTran]

The only size i dont remember using from 4.5mm to 24mm is 23. I have it but dont remember where it came from its a random non match to my sets. first post creeping for years finally made an account haha.

Ball joint nuts on Mazda 6 lower control arms are 23mm. I think that's the only time i've ever used a 23mm.