Impact Deep Socket Metric Sizes in Sets - Missing Increments in MM

[Lionelgee]

Hello All,

Firstly, the range of Deep Impact hex or "six point" sockets I am about to describe represent brands such as Genius - Force and even some "Unnamed" brands. I am not writing about 200 dollar plus for sets of 8 sockets like "Snap-On".

To further set the parameters of the following paragraphs: to avoid rounding off the flats of nuts and bolts that I have never worked on before, I intend to do the initial loosening with hex or six point sockets. I do not use impact drivers on the first loosening of these nuts and bolts; I use a breaker bar or a standard ratchet bar.

In an effort to increase my range of smaller sized deep impact hex or "six point" sockets I have spent a long time online to find sets that actually transition from 8 mm upwards in 1 mm increments to 22 mm. Apparently, this is a rare phenomenon. I have found that a common theme for Deep Impact socket sets is to miss 9, 11, 15 and 20 mm. These four sizes in the Deep Impact have to bought individually.

If I wanted to extend the range of Deep Impact sizes up to 32 mm between my current sets that I can put my hands to, I would have to buy: 23, 25, 26, 28, and 29 mm sockets individually.

Have the tool manufacturers carried out extensive research which has informed them that some sizes are so uncommon that they do not need to stock them in their "Sets"?

Here is a "For Instance": I just bought a new set of sockets online after visiting a number of specialist trade tool stores - not hardware stores in town... The online sourced "Set" includes:

Length: 78mm (Size: 10,12,13,14,15,16,17,18,19,21,22,24,27,30,32mm)
Length: 38mm (Size: 8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,2 7,30,32mm)

Notice that the 8, 9, 11, 20, 23, 25, 26, 28 and 29 mm by 78 mm long (Deep) sockets are not included in the set.
Also, that on the "standard" 38 mm long sockets are missing the 25, 26, 28, 29 and 31 sockets.

I do have some other sets that make up some of these gaps. However, most of these sets that I currently own start at 12 mm and go upwards to 32. None of my other sets of impact deep hex sockets started below 12. Hence, my intention of getting a set that went down to 8 mm. Earlier as a stop-gap measure, I had to go out and buy a 10 mm deep impact hex socket. With the 10 mm socket I was able to undo the smaller crankshaft and power steering pump bolts on my 1993 Defender 110 with a 200 TDI. These were bolts I figured would just love my using 12 point sockets on. So I went out and bought the hex or 6 point socket.

Otherwise, I would have thought that a socket set "Deep" or otherwise, would start with a low range socket size and build in 1 mm increments upwards to their stated highest or widest socket set. For example, from 8 mm to 32 mm.

No, I am not about to dash off to the tool shops or buy these "missing" sized sockets online in a single order. I will wait until the need arises - if the need arises. Mostly, because the combined cost of buying these "missing" sizes individually is more than most "sets" are worth.

It has me quite a bit miffed to be honest!

Kind regards
Lionel

[AK83]

You will probably find that many incremental metric sizes are not used, or so rare for many applications, not worth the effort.
Also, some metric sizes translate into AF sizes well too.

eg. is the 9mm, I doubt you will find a non worn or hacked up nut or bolt at 9mm.
11 is also fairly useless.
Maybe it could be secured to the fabled missing 10mm sockets so that there is less likelyhood for the 10mm to go AWOL. 11mm sockets is almost always the one you accidentally grab from the box instead of the 10mm(which is most likely not there anyhow!)

I used to think 18mm was also not worth having, but found a must have if you work on Euro cars too. For some reason they like to do things differently.

15mm is handy on a more modern LR. Can't recall all I've found, but definitely serpentine tensioner pulley nut.

Don't get caught up with fear of missing out due to your situation of missing increments, just concentrate on what you really need.

[DazzaTD5]

As mentioned some sizes are simply not used in the automotive industry.

Any decent mechanic should know all this, but as I rarely work on anything but Land Rovers, Jeeps, I have forgotten most of it all
Euro type vehicles use: 8, 10, 13, 16mm, 17mm, 21mm, 22mm
Jap use: 10, 12, etc etc

-----
Now I believe (but dont actually know) that aircraft use spanner sizes in between say normal metric sizes so the average mech cant work on them. So instead of a 12mm or 13mm they will use 12.5mm, 13.5mm. I have not researched this but my Dad apparently has a spanner set for aircraft somewhere in his shed.

[DieselLSE]

Now I believe (but dont actually know) that aircraft use spanner sizes in between say normal metric sizes so the average mech cant work on them. So instead of a 12mm or 13mm they will use 12.5mm, 13.5mm. I have not researched this but my Dad apparently has a spanner set for aircraft somewhere in his shed.

Alfa Romeo use some half sizes, too.

[ramblingboy42]

the reason the socket sets seem to miss sizes is because it is rare to find a hexagon head bolt or nut of those sizes.

I'm quite sure from my 45yrs as an engineering tradie that you will not use those sizes you seem to feel are missing from socket sets.

I have spanners and sockets that have never been used.

Save your money for something else.

A few months ago I gave my indy mechanic a bucket of assorted spanners, sockets and associated bits and his eyes lit up and I was happy to be rid of all the antiquated sizes and tooling.

[Geedublya]

You will probably find that many incremental metric sizes are not used, or so rare for many applications, not worth the effort.
Also, some metric sizes translate into AF sizes well too.

eg. is the 9mm, I doubt you will find a non worn or hacked up nut or bolt at 9mm.
11 is also fairly useless.
Maybe it could be secured to the fabled missing 10mm sockets so that there is less likelyhood for the 10mm to go AWOL. 11mm sockets is almost always the one you accidentally grab from the box instead of the 10mm(which is most likely not there anyhow!)

I used to think 18mm was also not worth having, but found a must have if you work on Euro cars too. For some reason they like to do things differently.

15mm is handy on a more modern LR. Can't recall all I've found, but definitely serpentine tensioner pulley nut.

Don't get caught up with fear of missing out due to your situation of missing increments, just concentrate on what you really need.

11mm is used on a lot of motorcycle brake bleed nipples.

[POD]

Years ago I bought a set of 1/4"drive sockets and it didn't include a 12mm, went from 11 to 13. Absolute joke. I made the rep throw one in. As for the others, I agree the missing sizes are mostly un-used or rarely used.

[PerthDisco]

My 30 year old Sidchrome 1/2” drive set still has imperial sockets without a scratch on one of them. Never used once in my lifetime so far.

[Lionelgee]

11mm is used on a lot of motorcycle brake bleed nipples.

Hello Geedublya,

When I resurrected a Yamaha DT250, a significant umber of years ago, the main tools were 10, 11, 12 and 13 mm sockets and spanners. With 8 mm sizes thrown into the equation to a lesser extent. Other larger sizes were used on the wheel bolts and the like. Photo - as per factory - accessed 17th February 2021 from, YAMAHA DT250 | Webike News

Kind regards
Lionel

[ramblingboy42]

a 12 is a very lonely spanner.

in imperial it is neither 1/2 nor 7/16

I have a very shiny 12mm spanner in my metric spanner drawer , I cannot recall using it.

I bought a set of long series metric sockets recently ....couple of years ago actually .....to facilitate accessing my spare wheel in one of its configurations I have used. There is a 12mm socket in the set , again not used.