When wrench sets skip sizes, how do they decide which to skip?

[GoodEnough]

http://www.harborfreight.com/7-piece-pro-gear-metric-stubby-combo-wrench-set-93922-2764.html

8mm, 10mm, 12mm, 13mm, 14mm, 15mm and 18mm


Who decides that?
What if you have a 16mm?
That would really piss me off.

 

[sselander]

It depends.
Asian cars would use 8, 10, 12, 14, 17, and 19

 

[MattPersman]

My thought is 16 is close enough to 5/8 so you get that in there sae set same with 19 close to 3/4, 17 is close to 11/16

 

[Harrison2]

id be more pissed theres no 17mm.

9 and 11mm are the ones i dont care for so they can gladly skip those.

 

[JBradley500]

I'm sure I'm not the only one but I really hate when they sell sets with 19mm in one and 3/4" in the other and theres no 18mm.

 

[GoodEnough]

9 and 11mm are rarely used?

 

[mech-tech]

I NEVER used any of my 9 mm or 11 mm wrenches or sockets

 

[Fedwrench]

9 and 11mm are rarely used?

It all depends on what you work on. Perhaps European vehicles use 9mm. I know I never use it. 11mm isn't used that much and is close enough to 7/16.

I mostly use 8, 10, 13, 15, and 18 but, that's GM and Ford light duty.

 

[cheechi]

I own 3 asian cars and a 'half asian' GM. Never use anything smaller than 8, nor 9, 11, 15, 16, 20, 22. There's a few standard size that are almost always 3/8 or 1/2 on my nissans though I can't think of anything offhand right now. 5/8 & 16mm are close enough that most spark plug sockets just have both sizes printed on them so it won't matter.

Some guys (I think Chrysler) every other fastener is a 15mm. Other sizes I swear it's only chosen because so few people have the socket or wrench so it's kind of a cheap way of making a security socket. 4mm is like that for some small electronics. A lot of sizes stop at 4.5mm or 6mm and don't go smaller.

Now I won't say that 'if you are missing a size you aren't a real man' or any foolishness like that but if you are a home hobbyist, you know what you personally are working on, you can get a set that skips the sizes you don't need. If you're satisfied with having only what you need, great. if you're like me and have to get every size, great. But the sets that skip sizes are usually because they can sell you an 'incomplete' set for less money, plain and simple.

 

[mech-tech]

For me, the smallest metric I need in a set is 8 mm, and thats for hose clamps and brake bleeders. Some brake bleeders are 6 mm, but not many. And as mentioned, 19 mm and 3/4" are very close. 10 mm is heavily used on battery terminals, 12 mm through 15 mm is REQUIRED for anything you will work on!!!!!!!!!!!!!!

 

[johno]

I've always assumed the sae and metrics are the same, just with different stamps.

If you work on Mercedes, you absolutely need a 17mm.

 

[kenburkholz]

Working on German, and Italian production equipment, I found the sizes most needed were,10,12,17,19,and 22mm. Ken.

 

[GoodEnough]

What's the 22 for ?

 

[Loscaldazar]

What's the 22 for ?

Subaru Tie Rods is the only one I know of.

 

[mech-tech]

Sometimes ya need big metrics, but mostly on heavy equipment or other large items. I used my 30 mm the other day, and big sets go up to 50 mm. By the way, 30 mm is the same as 1-3/16", but all SAE sets skip that size, so metric it was.

 

[nicksnothereman]

http://www.harborfreight.com/7-piece-pro-gear-metric-stubby-combo-wrench-set-93922-2764.html

8mm, 10mm, 12mm, 13mm, 14mm, 15mm and 18mm


Who decides that?
What if you have a 16mm?
That would really piss me off.

It's based on "common" fastener sizes. Remarkably, this is actually valid when it comes to cars (at least). That was the original intent, now it's probably custom. If you have an off size you pretty much have to buy a single or use something else.

I could be a douche and say you shouldn't even consider using a wrench (especially a stubby one) at 18mm on a torqued bolt if you can avoid it but I won't (or I just did...). You don't see that many (if any) large bolts without a decent amount of torque on them; I'm not going to mess up my shoulder trying to use a wrench trying to budge a fastener torqued to 80 ft/lbs underneath a car. Been there done that. That's why they make long breaker bars and 1/2" impact sockets (like butter).

 

[kamesama980]

8, 10, 12, 14, 17, 19, 21 will cover 95% of asian car repairs.

8, 10, 12, 14(?), 15, 18 is a european thing and some domestics have picked up the banner as well.

I've never used a 9mm or 11mm. I've never seen anything manufactured to use it. 7/16 and 11mm are just close enough to round the hex, not to do anything useful.

 

[Gmonkee]

In the 90's models 15 and 18mm were used less. Late 90's on Chrysler among others started to use 15 in place or 14 or 16, and 18 in place of 17 or 19mm. It has all to do with streamlining the assembly line operations and tooling requirements. Heavy equiptment made by Case started along that line of thinking too.

As older models are cut from production and newer models are introduced this trend will continue.

I've used 9mm on Ford while working in collision repair shops. Late 80's to early 90's models? It has been a while.

 

[d4dawg]

I know my VW brake line nuts are 11mm.

 

[Ft.ValloniaStreaker]

I work on German and Asian printing equipment 19mm and up are a must. And Subaru axle nuts are 32mm, you even need big wrenches on small cars.

 

[epmills]

9 is used on some brake bleeder screws, 11mm is much more common though, at least on Mercedes.

 

[transplant_wi]

I needed to add a 19mm for my Civic (lower ball joint nut). IIRC the hub nut is a 32mm but I found a close-enough inch socket to do the job.

 

[Outlander]

I thought it was designed like this to drive me crazy since I 'need' all the missing sizes! In fact I did need one missing wrench then I felt I should have all the missing ones. No wonder them call me by name at the tool section.....

 

[TAMPAGT07]

Who decides that?

The greek god of wrenches....Openendicus....

 

[Spinaker01]

I've always assumed the sae and metrics are the same, just with different stamps.

If you work on Mercedes, you absolutely need a 17mm.

BMW as well. Probably Audi also

 

[Rakoprtr]

What's the 22 for ?

Older toyota transfer and diff plugs

 

[metaldad]

What's the 22 for ?

squirrels.

 

[purplezr2]

8, 10, 12, 14, 17, 19, 21 will cover 95% of asian car repairs.

8, 10, 12, 14(?), 15, 18 is a european thing and some domestics have picked up the banner as well.

I've never used a 9mm or 11mm. I've never seen anything manufactured to use it. 7/16 and 11mm are just close enough to round the hex, not to do anything useful.

8 10 13 16 17 18 19 for VW some 9 and 12 in there but not often

 

[billp603]

One of my favorite quotes of all time is: "The great thing about standards is there are so many to choose from" Seems to be applicable for this subject as well

 

[NHBandit]

The set the OP mentions actually makes sense for a basic starter set except for leaving out the 17mm. 9, 11 & 16 are rarely used. The guy who said 15mm is uncommon must not work on GM or Chrysler stuff. It is what it is. An inexpensive beginner set. Most guys will fill in the blanks as they go.

 

[DeadSock]

An inexpensive beginner set. Most guys will fill in the blanks as they go.

I swear that it is planned that way ...
A "set" of 6 with 3 holes is $20, each hole is $15 ...

 

[jmm]

Working on German, and Italian production equipment, I found the sizes most needed were,10,12,17,19,and 22mm. Ken.

What you working on Ken? I work on German looms and French jacquard heads for a living (mess with an Italian extruder and fabric tumbling machine a little, too).

I use almost all my wrenches at some point, but I also use the hell out of a 10, 12, 17, 19, and 22. My 7, 8, and 13 mm wrenches also see a lot of use.

 

[paranoid56]

8, 10, 12, 14, 17, 19, 21 will cover 95% of asian car repairs.

8, 10, 12, 14(?), 15, 18 is a european thing and some domestics have picked up the banner as well.

I've never used a 9mm or 11mm. I've never seen anything manufactured to use it. 7/16 and 11mm are just close enough to round the hex, not to do anything useful.

kinda random, but i was taking a break bleeder off my old fj40 and they were 9mm and the clutch master bleeder was 11. was glad i still had that one flare wrench

 

[ndoran]

It's based on "common" fastener sizes. Remarkably, this is actually valid when it comes to cars (at least). That was the original intent, now it's probably custom. If you have an off size you pretty much have to buy a single or use something else.

I could be a douche and say you shouldn't even consider using a wrench (especially a stubby one) at 18mm on a torqued bolt if you can avoid it but I won't (or I just did...). You don't see that many (if any) large bolts without a decent amount of torque on them; I'm not going to mess up my shoulder trying to use a wrench trying to budge a fastener torqued to 80 ft/lbs underneath a car. Been there done that. That's why they make long breaker bars and 1/2" impact sockets (like butter).

GM use a 18mm nut on the ball joint on the GM cavalier, cobalt etc. You either need a extra long wrench or a ring crowfoot to fit it because the outboard CV joint prevents you getting a socket onto it.

 

[ajchien]

My thought is 16 is close enough to 5/8 so you get that in there sae set same with 19 close to 3/4, 17 is close to 11/16

Yeah, I've got an old Crescent 3/8" drive metric/sae set thats pretty well thought out like that. It's missing the 8,16,19 - but its got the 5/16, 5/8, and 3/4 in the set.

 

[ajchien]

Oh, yeah, this chart might be useful. It compares bolt sizes and ANSI/DIN/JIS bolt heads:

http://www.engineeringtoolbox.com/metric-bolt-head-wrench-size-d_1458.html

 

[Deskmechanic]

When I was younger I was into restoring Vespas - 11mm was used all over those things. It's the standard head on an ISO 7mm hex head screw/bolt. But pretty much no other vehicle uses them in any quantity.

 

[bobemmerich]

yep, Chrysler and GM love the 15mm!

 

[RPH]

Work on European Induction heating equipment. Start at 4 mm and use everyone up to 32mm. I carry two 16 mm because they use a but full of them.

 

[shamrock12]

I wish they could just keep it simple by just including every wrench sizes without skipping. Just because you don't need some certain sizes right now doesn't mean you will need them in the future. There is really no way that most tool companies would be able to determine what sizes you would be using because that would mean they need to set up certain sets for specific appliciaton (automotive, agricultural, construction, etc) and that would be subject to more inventory.