Is their anything wrong with an 18mm socket?

I changed my track rod the other day.

Getting the rod off was easy enough - I undid the nut with an 18mm spanner
A few blows with a hammer and it was off.

Then it came to putting the new one back on - and getting the torque right.

Ah! Out comes my trusty torque wrench and I start the vain search for an 18mm socket.

I have 3 socket sets that go up to 19mm - none of them have an 18mm
None of the imperial sockets in the same set fitted the nut.

In the end I wrapped tin foil around the nut, squeezed my cheapest 19mm socket on and, happily, it worked!

but my question is, why do socket sets omit the 18mm socket?

Its not like the included spark plug socket fitted nor an imperial one!

Perhaps there is something special about 19mm ones?

Is it a marketing ploy?

Its been bugging me can you tell?

Anyway, hopefully Santa will bring me an 18mm socket

my halfords sets all have 18mm included

some of my socket sets miss the 18mm, and one skips the 16mm, never sure why. I have a big box of random assorted sockets and wrenches I picked up from a charity shop for a fiver though and after a rummage I can usually find what I'm after.

both my sets have 18mm... maybe you just need to invest in a better socket set?

It's because it's an uncommon size. If they can miss a few out which the consumer is unlikely to use anyway then it saves them money and can sell the socket set at a lower price.

As mentioned above, 16 is also missed out sometimes, along with 1 or 2 others.

There's no discrimination towards 18mm lol. It's just that the majority of manufacturers use common sizes such as 10, 13, 15, 17, 19 and a scattering of others here and there

PS. Imperial size 11/16 would also fit an 18mm

had an 18mm in my tool chest, but needed it fer working on me then mondeo.
engine mounts I think.
so I used it on me impact gun.... wrong - it split
so i found some gas barrel pipe that i got to fit over the outside, welded one end on...

Its the most easily found 18mm socket in that tray "still"

I did buy a propa impact socket in the end, as I buy one offs as I need `em too.

got one old style cantilever toolbox full of just sockets/wreneches/T bars/ extentions, some made up wierd an wonderfull 1/2 inch drive sockets an stuff I made over the years..

coz I`m a kinda can do guy.... Hummphhh...

if normal sockets cant do it, out comes the cutting saw & welder =
job done - sorted - tools away..

Get the ones I'm missing from westcountry hardware on eblag do all sizes sockets separately.

SteDisco said:

PS. Imperial size 11/16 would also fit an 18mm

Click to expand...

no it wont, it will fit a 17mm though

when the slitties started selling cars in the UK, it was amazing as to how small the bolts were on some applications.
we were used to 1/2 inch-13mm,
they used 10mm or 12 mm instead,
even now more car makers used strange sized nuts & bolts in car assemblies.

If "we" still built steam engines, we would still be using traditional huge nuts & bolts I guess, but size is now a burdon,
all up weight is reduced to the max,
so we ended up with small nuts

oh, and plastic cars.......


many many years ago I lived near Fords test track in essex
BBC - Essex - In Pictures - Forty years of Ford at Dunton
and the local paper (ass wipe of a rag) printed a story of them testing plastic bodied cars there.....................we all laughed, how silly.. :hysterically_laughi
but in the end, we ended up with,
plastic bodied cars, even glued together cars, & planes....


anyone got a spare 12mm spanner, i`ve worn mine out

Standard head sizes:

Metric Thread Pitch and Spanner Sizes for Standard ISO and Japanese

scotty281976 said:

no it wont, it will fit a 17mm though

Click to expand...

Apologies, a while since I've used imperial tools.

as above its to dowith the standard head sizes on metric bolts ...if the designer was a proper engineer .you should never need a 16 or 18 socket on a metric bolt or nut.... when metric started to take over from sae fasteners 14 and 15 were seldom used either,

back then we all still had whitworth spanners aswel as af cos twas common to find all three systems of nuts and bolts

whitworth was the british standard. whitworth and BA threads

SAE was the american system unc and unf threads with af spanners

metric was the european standard

when you get onto pipe threads it gets complicated....

ricc said:

as above its to dowith the standard head sizes on metric bolts ...if the designer was a proper engineer .you should never need a 16 or 18 socket on a metric bolt or nut.... when metric started to take over from sae fasteners 14 and 15 were seldom used either,

back then we all still had whitworth spanners aswel as af cos twas common to find all three systems of nuts and bolts

whitworth was the british standard. whitworth and BA threads

SAE was the american system unc and unf threads with af spanners

metric was the european standard

when you get onto pipe threads it gets complicated....

Click to expand...

I still use a Zeus book
Zeus Precision Data Charts and Reference Tables for Drawing Office, Toolroom & Workshop: Amazon.co.uk: Zeus Precision Charts Ltd.: Books

always one in my toolchest!

used one fer as long as I can remember,
no need fer PC, laptop, ferking all singing & dancing iphones.

Its the engineers tool...

oops, found this

http://www.green-oval.com/data/zeus.pdf
fer all you young techie blokes... LOL

ricc said:

as above its to dowith the standard head sizes on metric bolts ...if the designer was a proper engineer .you should never need a 16 or 18 socket on a metric bolt or nut.... when metric started to take over from sae fasteners 14 and 15 were seldom used either,

back then we all still had whitworth spanners aswel as af cos twas common to find all three systems of nuts and bolts

whitworth was the british standard. whitworth and BA threads

SAE was the american system unc and unf threads with af spanners

metric was the european standard

when you get onto pipe threads it gets complicated....

Click to expand...

Great explanation of this issue and I agree wit easy about the sizes getting smaller, wtf use is an 8mm bleed nipple
Just to muddy the waters even more I should mention that I have a digital caliper and have found quite large differences even within a single size, both met and imp. My approach is to have Whit and AF sets on standby in the workshop for the really hard to size ones.

Rattlegun said:

Standard head sizes:

Metric Thread Pitch and Spanner Sizes for Standard ISO and Japanese

Click to expand...

thats what got me laughing,
had one of them once, it wer called me house,
sold 10 years ago, bought a tiny one instead..

but the headlines -
4 ways to avoid running out money in retirement..

DONT buy a landie..................ffs.............lol...


joking really guys....ound:
about the landie bit..cheap as chips to run they are,
speshley if you live neara chip shop or 2...

it's the same with a 7mm allen key. (caliper bolts on me astravan). Had to go to three places before I found a set with a 7mm.

So in a nutshell...

I have old socket sets made by penny pinching manufacturers who took advantage of metrification to skimp on a metric equivalent to an uncommon imperial size despite the fact that all the imported cars were metric and used every size they could think of including 18mm, then years later Landrover finally caught up with metric and decided to use it on a disco track rod - but probably not just to upset me.

Nice!

TaDa said:

So in a nutshell...

I have old socket sets made by penny pinching manufacturers who took advantage of metrification to skimp on a metric equivalent to an uncommon imperial size despite the fact that all the imported cars were metric and used every size they could think of including 18mm, then years later Landrover finally caught up with metric and decided to use it on a disco track rod - but probably not just to upset me.

Nice!

Click to expand...

more likely its the same trackrod end they used on a series in 1948 with a whitworth nut that an 18mm just happens to fit


i had a hilka socket set back in the seventies ... with a set of af sockets and all the even numbered metric ones that were never used...no 13,17, or 19 work that one out.

18mm is virtually the same as 5/8 whitworth. In fact some sockets come marked 5/8 whit / 18mm. There are two whit sizes that have almost direct mm replacements 28mm being the other. Have a look at the conversion charts here