Why is a 10mm Socket in 1/2 Drive a standard?

[hahmed]

Why do 1/2 drive socket sets start at 10mm?

Yet these same sets will skip 16mm, 17mm, or 18mm.

Is there really a very common use case for 10mm sockets used in 1/2 drive? Why would you possibly want to use a 1/2 ratchet or bar on a 10mm fastener? Unless you intend to break the head. Only use I can think of is for engine fasteners like rod bolts that are stronger alloys.

To me, a weekend warrior, it seems like these companies are packaging sets to make you spend more money for less tool utility. So you end up buying the very common 21mm and 32mm sockets.

 

[Dave455]

If you have a 1/2 inch drive socket set, and no other, and you want to undo a bolt with a 10mm head, you need a 10mm socket! Simple.

I think that just about every 1/2 inch drive socket set I’ve ever encountered includes 10mm. It’s a standard size in just about every standard there is (ISO, DIN, JIS etc) unlike 16 and 18, which are not used in every standard, hence those sizes are sometimes skipped.

Most SAE 1/2 inch drive sets start at 3/8, and that’s probably less used than 10mm!

Yes, a 3/8 drive set might be more appropriate for 10mm, or even 1/4, but if I’m heading out to do a job I regularly take just one set with one drive size, and I want it as comprehensive as feasible!

 

[ssdave]

....

 

[Fedwrench]

I think it's because 3/8 drive isn't as popular in other places as it is here. In fact there have even been threads about living without 3/8 over the years.

 

[LJSE34]

It's a backup for when you've lost both your 1/4 and 3/8 10mm sockets

 

[Temaweaver]

1/4” drives up to 7/16”
3/8” drives 3/8 up to 3/4”
1/2” drives 9/16 up

This would work for me.

 

[hahmed]

Reason for my complaint is that using a 10mm in 1/2 is asking for trouble in most cases. You may not realize how much torque you are putting down on fastener that is seized. The head will shear before you realize you need a different technique like heat.

Also for taking a 1/2 inch set to a job, I’d argue to take a 3/8 set covering 10-19mm to do 90% of jobs.

I’m not saying 10mm shouldn’t exist in 1/2 inch. But it shouldn’t be a starter socket set, drop the 10mm and add a 21mm or another between 15-18mm. Don’t give me a socket that will screw me over most times. Especially in impact.

I would say start a 1/2 set from 12mm.

 

[shawhite]

My 1/2 snap-on set starts @ 12mm. I don’t ever see the need to use a 10mm on a 1/2 in ratchet unless I didn’t have another option. A lot of times I will use my 1/4 drive on 10mm unless I think I will need the extra leverage of a 3/8 drive

 

[Plumber4]

The few times I've used a 1/2" ratchet with a 10mm I hold the handle closer to the head to limit leverage. I share the same concern of breaking the bolt head.

 

[ssdave]

....

 

[sparky 1971]

It's cheaper to put the smaller sockets in a set. People look at the packaging and think it's a better deal. My 1/2" chrome metric set goes from 10-32 mm. The impact set might be the same. I doubt if I have ever used the 15 or smaller. I would rather pay a little less and do without the filler that I probably will never use, but it is what it is.

If I were to use the 10mm, is there more chance of breaking the fastener with my 11" long 1/2" drive ratchet or my 13" long 3/8 drive? If it's stuck so bad it breaks before coming loose, it's going to break no matter what the drive size.

 

[dnschmidt]

Fed, got this right. In the rest of the world, particularly Asia, 1/2 drive is FAR more popular than 3/8" drive. When I sold TOPTUL, an extremely high quality brand made in Taiwan, they had ton's of 1/4" drive stuff and tons of 1/2" drive stuff but relatively little in the way of 3/8" drive. This is common in Asia and to some extent in Europe as well. Seems nuts to an American where 3/8" drive is king. But, as we are reminded of more every single day, American isn't the center of the world anymore.

 

[Lucid Moments]

My guess is simple convenience. If you have the 1/2" ratchet in your hand and need a 10mm socket it is easier to just slap a socket on it than to grab another ratchet and another socket. Particularly if you grabbed your whole rack of 1/2 sockets and took them to the job with you.

 

[richfinn]

Useful at the junkyard when you want to snap the heads off 10mm bolts with a powerful impact, so you can get at the treasure!!!

When installing new brake lines, we would cut the lines close to the fitting and hammer a 1/2 drive impact socket on and zip them straight out to save fighting with flare nut wrenches (often 11mm on Euro cars)

 

[woody6904]

Fed, got this right. In the rest of the world, particularly Asia, 1/2 drive is FAR more popular than 3/8" drive. When I sold TOPTUL, an extremely high quality brand made in Taiwan, they had ton's of 1/4" drive stuff and tons of 1/2" drive stuff but relatively little in the way of 3/8" drive. This is common in Asia and to some extent in Europe as well. Seems nuts to an American where 3/8" drive is king. But, as we are reminded of more every single day, American isn't the center of the world anymore.

I went the 1/4 and 1/2 route on the service truck and got to say I'm liking it. Frees up a little space, simplifies things. Knock on wood have only ran into one situation where I needed a 3/8 drive adapter and extension to take out a fill plug on a corn head.

 

[Al Borland]

Because before 10 MM became the most popular socket to lose, 1/2" was the missing socket.
OCD kicks in when a socket is gone, and the sheeple go buy another set.
Basic marketing 101.

 

[Downwindtracker 2]

I have couple of SAE socket sets, one from late '60s another from the mid '80s, both started at 7/16, the head size for 1/4" bolt . In place of 1/4" bolts they now use 6mm bolts, with a head size of 10mm.

 

[hahmed]

If I were to use the 10mm, is there more chance of breaking the fastener with my 11" long 1/2" drive ratchet or my 13" long 3/8 drive? If it's stuck so bad it breaks before coming loose, it's going to break no matter what the drive size.

I would respectfully disagree here. But if you are careful with a long ratchet or bar I see that as a comfort options. I do that myself but am careful of how the force is multiplying.

It is safest to start with a more standard length ratchet on 3/8" then go with heat or penetrant. Breaking a bolt head and using an extractor is more trouble than grabbing penetrant or a torch. If that fails I would pray and go with a bigger bar. In that case you have little choice, it either opens or breaks.

 

[lardy1]

It's cheaper to put the smaller sockets in a set. People look at the packaging and think it's a better deal. My 1/2" chrome metric set goes from 10-32 mm. The impact set might be the same. I doubt if I have ever used the 15 or smaller. I would rather pay a little less and do without the filler that I probably will never use, but it is what it is.

If I were to use the 10mm, is there more chance of breaking the fastener with my 11" long 1/2" drive ratchet or my 13" long 3/8 drive? If it's stuck so bad it breaks before coming loose, it's going to break no matter what the drive size.

This makes sense to me. The length of the handle, regardless the drive size, is going to determine the force applied. The 3/8 specified should break the bolt easier than the 1/2 specified. I'm sure an engineer can make my reply seem stupid but it seems common sense to me.

 

[cgv69]

Fed, got this right. In the rest of the world, particularly Asia, 1/2 drive is FAR more popular than 3/8" drive.

I wonder if its a strength thing?

When I was younger and stronger, the only 1/2 drive stuff I owned was impacts and that was only used for really large/stuck bolts. I used 3/8 or 1/4 drive tools for almost everything.

Now that I'm older and weaker, I have a full set of 1/2 drive tools and often find myself using the 1/2 drive tools in situations that I would have used a 3/8 before.

To the OP... No, I have never used 1/2 drive stuff on a 10mm size nut and don't know why I ever would? To me, 10mm is 1/4 or 3/8 territory but I guess to other's point, if that's all you have?

For people on a budget, I can definitely see the logic behind having a complete 1/2 set and 1/4 set and skipping the 3/8 all together.

 

[ex-x-fire]

Some bolts like these wheel bearing bolts have small 10mm heads for clearance.

 

[theoldwizard1]

1/4” drives up to 7/16”
3/8” drives 3/8 up to 3/4”
1/2” drives 9/16 up

My 1/4" drive goes up to 9/16"
My 3/8" drive goes down to 1/4"
My 1/2" drive goes down to 3/8"

 

[sparky 1971]

I would respectfully disagree here. But if you are careful with a long ratchet or bar I see that as a comfort options. I do that myself but am careful of how the force is multiplying.
.[/QUOTE

What do you disagree with? It's possible to generate more torque with a 13" handle than an 11"? It's been over 30 years since I took anything that even resembles a physics class so maybe I have forgotten a thing or two.

 

[Wrench97]

I use a 1/2" 10mm all the time, the only real purpose is to keep me from changing drive tools since in the shop I use almost exclusively air. Again let common sense prevail, don't hammer it.

 

[nbpt100]

This makes sense to me. The length of the handle, regardless the drive size, is going to determine the force applied. The 3/8 specified should break the bolt easier than the 1/2 specified. I'm sure an engineer can make my reply seem stupid but it seems common sense to me.

You make perfect sense. You may want to substitute torque for force but that is nuanced.

This is common in Asia and to some extent in Europe as well. Seems nuts to an American where 3/8" drive is king. But, as we are reminded of more every single day, American isn't the center of the world anymore.

Exactly and many of US Americans need that reminder.

Because before 10 MM became the most popular socket to lose, 1/2" was the missing socket.
OCD kicks in when a socket is gone, and the sheeple go buy another set.
Basic marketing 101.

Some company (i don't recall-maybe more than one) even sells a 10mm socket replacement kit. It has just about every 10mm socket you can think of. 12pt, 6 pt, flex head sockets in 1/4 to 1/2 drive. Someone here will remember who it may be.

I fully understand the OP's point. But there are many others too. People complain about not having the socket they need at the time. Not having too many.

Except when I use my impact, I can pretty much survive on 1/4 and 3/8 drive.

 

[M6erfan]

Fed, got this right. In the rest of the world, particularly Asia, 1/2 drive is FAR more popular than 3/8" drive. When I sold TOPTUL, an extremely high quality brand made in Taiwan, they had ton's of 1/4" drive stuff and tons of 1/2" drive stuff but relatively little in the way of 3/8" drive. This is common in Asia and to some extent in Europe as well. Seems nuts to an American where 3/8" drive is king. But, as we are reminded of more every single day, American isn't the center of the world anymore.

This is the way I work too. It just happened naturally over the years in my shop. 1/4" reigns up to 12mm, 1/2" takes over at about 14mm, with some overlap. 3/8" drive is used the least, and generally for specialty sockets like spark plugs, crows foot, etc., and torque wrench applications.

 

[hahmed]

This makes sense to me. The length of the handle, regardless the drive size, is going to determine the force applied. The 3/8 specified should break the bolt easier than the 1/2 specified. I'm sure an engineer can make my reply seem stupid but it seems common sense to me.

You are absolutely correct it is length of the lever.

I would respectfully disagree here. But if you are careful with a long ratchet or bar I see that as a comfort options. I do that myself but am careful of how the force is multiplying.
.[/QUOTE

What do you disagree with? It's possible to generate more torque with a 13" handle than an 11"? It's been over 30 years since I took anything that even resembles a physics class so maybe I have forgotten a thing or two.

Sorry I mean't I disagree with the approach of approaching a 10mm bolt with a long handle regardless of drive size. It's why I don't like 10mm offered in 1/2 drive as most 1/2 drive ratchets are long length bars compared to 1/4 drive.

This is just personal opinion really. As for some a longer bar and being careful works just as well.

What I fear really is someone starting out wrenching who picks up a 1/2 drive set and wrecks 10mm bolts. I actually have seen this with friends using the wrong tool while having little sense of torque as it's their first time wrenching anything ever.

 

[MikeF2316]

I like having my 10 mm 1/2" drive, but I agree, 15, 16 & 18 would all be better in a starter set.

Generally, I use 3/8 drive up to 17, 1/2 drive from 18. Except suspension where I'd pick 1/2 drive for 17.

 

[englishsam]

In the UK it's not uncommon for mechanics to only have 1/2 impact guns. 3/8 is more common now but 1/2 is pretty much the standard. I have a full set of 3/8 impact sockets but that is not usual.

Different places do different things in different ways.

If I were to use a 17mm socket on 3/8 people would think me very very strange here.

 

[dscheidt]

Fed, got this right. In the rest of the world, particularly Asia, 1/2 drive is FAR more popular than 3/8" drive. When I sold TOPTUL, an extremely high quality brand made in Taiwan, they had ton's of 1/4" drive stuff and tons of 1/2" drive stuff but relatively little in the way of 3/8" drive. This is common in Asia and to some extent in Europe as well. Seems nuts to an American where 3/8" drive is king. But, as we are reminded of more every single day, American isn't the center of the world anymore.

I used to work with a German guy who made fun of us for using 3/8 drive for everything. He didn't have any 3/8" drive ratchets, using 1/4 and 1/2. He'd always have to borrow a ratchet and extension whenever he needed to use a special socket that only came in 3/8 drive. Someone eventually gave him one for his birthday, which everyone but him found hilarious.

I will say his nagging taught me to use 1/4 drive a whole lot more than I used to.

 

[Kev442]

My 6 point 1/2" 10mm is about worn out. Many many caliper bolts. Reach in, set it on and give a good yank. 3/8" drive tends to want to go cockeyed on me doing that, which results in me whacking my knuckles and being upset.

 

[mazdeuce]

If I look at catalogs, including German and Japanese ones, the overwhelming majority of speciality automotive sockets are 3/8 drive. What do people do without a 3/8 ratchet?

 

[AldeanFan]

When I worked in a taxi shop in the late 90’s We only had air tools and most guys only had a 1/2” impact, I knew 3/8 impacts existed but didn’t know anyone who had one.

To keep production up we used the impact a lot, both on old rusty bolts when doing maintenance and on new bolts for assembly.

I probably drove ten 5 gallon buckets of self tapping screws while I worked there, using a 3/8” socket on a 1/2” impact gun.

I can probably still remove a fender from a Chevy caprice with my eyes closed. It’s all 10mm bolts and I remember wishing I had a 7mm 1/2” drive socket so I could do the trim screws with the impact to speed things up!


Sent from my iPhone using Tapatalk

 

[ex-x-fire]

I have one for you, was doing a door stop in a Transit. The 10mm headed bolts holding it in were the typical bolts for 1/4 inch drive. But they were loctited in place. Yes, I could have used the 1/4 inch to remove them, but I was nearing is max on the ratchet in my opinion. 3/8 did the trick and no broken tools.

 

[Ralf11]

If I look at catalogs, including German and Japanese ones, the overwhelming majority of speciality automotive sockets are 3/8 drive. What do people do without a 3/8 ratchet?

when I was a poor 'kid' I used a 1/2" drive ratchet and an adapter

 

[ex-x-fire]

when I was a poor 'kid' I used a 1/2" drive ratchet and an adapter

Most of the kids in my hs autoshop did that.

 

[MarvinBerry]

I’m not saying 10mm shouldn’t exist in 1/2 inch. But it shouldn’t be a starter socket set, drop the 10mm and add a 21mm or another between 15-18mm. Don’t give me a socket that will screw me over most times. Especially in impact.

The easy answer is don't buy starter sets. Then the question is what kinda cheap o "starter sets" are you buying that have that many skips?!

I have a Kobalt deep rail that was inexpensive and goes 10-21... might've only been 30 bucks. How much cheaper can ya get?

For the average person 10mm is more common then bigger stuff. And most guys & gals on this board aren't buying starter sets... kind of a lost argument.

 

[Semi-hole mechanic]

I grew up on a farm in the 70s and we used 1/4 or 1/2 drive. I have a pretty comprehensive collection of 1/4 deive sockets SAE/MM, shallow and deep. The same in 1/2, but in 3/8 I only have a few deep wells in SAE and all of my MM aré all shallow. I just usually grab 1/4 or 1/2 because they already overlap a little. The other day I did use my 3/8 drive 13mm socket while replacing the water pump on the GFs liberty because of clearance until I broke it and then had to finish with the 1/2 drive.

 

[hahmed]

The easy answer is don't buy starter sets. Then the question is what kinda cheap o "starter sets" are you buying that have that many skips?!

I have a Kobalt deep rail that was inexpensive and goes 10-21... might've only been 30 bucks. How much cheaper can ya get?

For the average person 10mm is more common then bigger stuff. And most guys & gals on this board aren't buying starter sets... kind of a lost argument.

Skipping sizes is very common on offerings by German and Japanese tools.

Also extremely common at big box store sets.