Has anyone ever needed a 9mm hex key?

[tanukiboy]

Like many people here at GJ, I have a severe case of OCD. I recently read a number of threads concerning which metric wrench sizes were never used (the consensus seemed to be 9mm, 11mm, 15mm, and 20mm).

But, this being GJ, many people immediately chimed in with posts like "I just used a 20mm combination wrench to tighten the turn signal fluid filler on my Russian bus" or "I use 9mm all the time to change the filters on my Icelandic milking machine."

Well, that was good enough for me! Having been a member of GJ for a while now, I already had 11mm, 15mm, and 20mm. So I decided I needed a full set of 9mm wrenches too: combination, DBE, ratcheting, reversible offset ratcheting, flex head ratcheting, regular socket, and deep socket -- all in both 6pt and 12pt.

After all, if I ever needed a 9mm wrench and didn't have it sitting right there between 8mm and 10mm, my life would be meaningless and I'd have to kill myself. You might say I could just use one of my Knipex pliers wrenches or one of my Top Hyper Monkey Zero adjustable wrenches? NO WAY!

With that potential tragedy taken care of, I now notice that I don't have any 9mm hex keys, or even hex bits. What!

With some trepidation, I have to ask: has anyone here ever needed a 9mm hex key?

 

[tesla's ennui]

Volvo transmission bolts

 

[tanukiboy]

Volvo transmission bolts

Dammit! I knew I was just asking for it. Looks like Amazon gets more of my money. I don't own a Volvo, but I might someday.

PS. It only took 11 minutes!

PPS. And the final nail in the coffin is that they don't make adjustable hex keys.

 

[rpcraft]

Not specifically for a 9mm because I don't recall ever seeing one but I imagine it could be useful if you had a somewhat stripped SAE socket bolt and needed to pound the 9mm in a desperate attempt to get it out but then again you could probably get better results at that point with an extractor.

 

[tanukiboy]

Not specifically for a 9mm because I don't recall ever seeing one but I imagine it could be useful if you had a somewhat stripped SAE socket bolt and needed to pound the 9mm in a desperate attempt to get it out but then again you could probably get better results at that point with an extractor.

Yeah, the old "rusted/damaged/stripped fastener" argument gets me every time!

 

[Super Mech]

Ford Escape caliper bolts.

 

[Negen]

I use hex keys all the time on random stuff. I got so frustrated that I bought quite a bit of what I would think and hope is a complete set of hex keys. I am sure there will be a day when I need a hex key and won't have the proper size though.

.028"-5/8" 18 piece eklind Short

.07mm-17mm 15 piece proto short (eklind rebrand)

.09mm - 17mm eklind long 14 piece set

5/64"- 5/8" proto socket




Sent from my G8141 using The Garage Journal mobile app

 

[PFSard]

With some trepidation, I have to ask: has anyone here ever needed a 9mm hex key?

I didn't even realize I had one. I don't ever remember using a 9 mm hex key.

 

[Ign]

Actually yeah. On some '99 and earlier Ram 1500 4x4's the caliper bolts take a 9mm hex.

Drove me crazy one day 'til I figured this out. However the HELP! oversized thread-cutting bolts (commonly needed) go to a more standard 10mm or something

 

[nbpt100]

If Lisle makes it, for sure it has an automotive application. Funny how they are used on US made cars. Everybody would expect them on a European car.

https://www.amazon.com/dp/B005ADY968/?tag=atomicindus08-20

 

[Ign]

"I'm intercontinental and I eat French toast!"

 

[American Locomotive]

A 9mm hex head cap screw doesn't appear to be a valid ISO, DIN, ANSI/ASME or JIS size. Any company who uses that size is just being a jerk.

 

[nbpt100]

A 9mm hex head cap screw doesn't appear to be a valid ISO, DIN, ANSI/ASME or JIS size. Any company who uses that size is just being a jerk.

I know, I also looked myself. They must have a deal with the tool vendors.

At least it is not an expensive tool.

Try owning a German car. Just look at all of the specialty tools they use.... and they are not cheap!
So look on the Bright Side!

 

[Dakkyz]

I have come across 15mm and 20mm Hex Bolts, mainly old Renault mascott and Iveco equivalent Recovery trucks they're used on the back to hold down the spec for the 20mm and 15mm and some were body bolts.

AS these were custom built I find it unlikely you will ever come across these in the wild.

 

[Jazz1]

I dont know. Made me look and I see the 9mm is skipped in both my sets so i guess the 5/16" may come into play or my next trip to the pawn shop i will be checking the .50 bins

 

[nbpt100]

5.5mm (in both the internal and external hex) is another one that is usually skipped but it is very close to 7/32.

 

[American Locomotive]

I dont know. Made me look and I see the 9mm is skipped in both my sets so i guess the 5/16" may come into play or my next trip to the pawn shop i will be checking the .50 bins

5/16" is basically exactly 8mm. 3/8" is closer to 9mm, but probably won't fit into a tight tolerance screw.

 

[DFB]

Weird, I have 4 different metric hex drive sets, 9mm is skipped in everyone of them

 

[unslow1]

Ford Escape caliper bolts.

The Mariner also.

 

[unslow1]

A 9mm hex head cap screw doesn't appear to be a valid ISO, DIN, ANSI/ASME or JIS size. Any company who uses that size is just being a jerk.

Ford did just to be a pain. They are a bit hard to find when in a hurry with the vehicle apart in your driveway.

 

[Ign]

I dont know. Made me look and I see the 9mm is skipped in both my sets so i guess the 5/16" may come into play or my next trip to the pawn shop i will be checking the .50 bins

5/16" for all practical purposes is pretty much exactly 8mm so it won't really do much as a substitute for 9

If anyone here wrenches or thinks they might wrench on 2nd gen Rams I'd just order one so you're not left out in the cold like I was. I consider myself extremely well-tooled in most hand tools and most auto-specific tools and was shocked to see Dodge be such assholes as to specially make 9mm hex caliper bolts.....kinda like Milwaukee and their 2438 sander w M9 spindle threads!!

 

[eschoendorff]

Ford Escape caliper bolts.

Yup same here. I Own two escapes.

 

[Ign]

eschoendorff returns from the dead!

 

[American Locomotive]

Weird, I have 4 different metric hex drive sets, 9mm is skipped in everyone of them

As I mentioned earlier: ISO, DIN, JIS and ANSI/ASME have basically all agreed that 9mm socket head screws are not, and should not be a thing. So it makes sense most tool sets will not include those sizes - since they're non-standard. Some automakers apparently think differently.

 

[BigBoreFan]

I don't recall ever needing a 9mm hex key, but it won't break me to buy one.

I used a 15mm combo the other day on a bicycle axle and I use a 20mm on my European Motorcycle. I don't recall ever using a 16mm, and 18mm one time only, but I don't work on cars much.

 

[L.Cheapo]

Actually yeah. On some '99 and earlier Ram 1500 4x4's the caliper bolts take a 9mm hex.

Drove me crazy one day 'til I figured this out. However the HELP! oversized thread-cutting bolts (commonly needed) go to a more standard 10mm or something

Interesting. My 98 has its original caliper bolts and I've always used 3/8 in them. Wonder if it had to do with bolt tolerances or what factory made the truck.

Snap-on includes the 9mm in their hex bit sets.

 

[Ign]

Tear TTB outta numerous '80-96 Fords (SAS baby!) and you'll wear out 15mm and 18mm combo wrenches LOL

 

[Ign]

Also I see my 9mm is a PT (Performance Tool). I likely grabbed it at O'Reilly, and IIRC I used a $5 reward from O'Rewards so it was kinda "free"

 

[DFB]

Interesting. My 98 has its original caliper bolts and I've always used 3/8 in them. Wonder if it had to do with bolt tolerances or what factory made the truck.

Snap-on includes the 9mm in their hex bit sets.

I must have done the same thing



3/8 (.375) = 9.525mm

 

[Ign]

Interesting. My 98 has its original caliper bolts and I've always used 3/8 in them. Wonder if it had to do with bolt tolerances or what factory made the truck.

Snap-on includes the 9mm in their hex bit sets.

Yep before posting I did a Google search to make sure I was remembering right. There's a smattering of people on several Mopar-specific forums that say 9mm, while others say theirs are 3/8 for sure.

So it appears to be a limited run, or as you said factory dependent etc. The vehicle in question for me was a '99 and 3/8" was NOT fitting, several hex key manufacturers

Come to think of it I've COMPLETELY gone thru the front brakes on my non-profit's '98 and never had an issue and this was long before I purchased the 9mm. So I don't remember what THAT '98 was but it was NOT 9mm

 

[DFB]

Haha I just went and mic'd 3 of my 3/8" hex sockets just to see what they read

 

[rpcraft]

It would be a little loose. Too loose depending on what you are breaking loose or tightening, but if it was something just hand tight or snug (meaning not 800 pound gorilla tight) you could do fine with it.

 

[eschoendorff]

eschoendorff returns from the dead!

Lol. Yeah. Sorry bout that

 

[ku17]

You’re definitely going to need a 9mm hex socket for post-tensioning muffler bearings. Wouldn’t want to be caught without one.

 

[Banshee365]

I’ve used 11mm on 6.0 Powerstroke charge air cooler hose clamps. 7/16” may work but it’s slightly larger than 11mm and the 11mm fits really well.

I’ve also used 15mm quite a lot on VW’s.

I can’t tememebr a time that I used a 9mm tool. Maybe I have but I don’t recall. I have several sockets and wrenches when/if the time comes though.

 

[bwringer]

A 9mm hex head cap screw doesn't appear to be a valid ISO, DIN, ANSI/ASME or JIS size. Any company who uses that size is just being a jerk.

Yup. When I am King of the World, I will immediately outlaw the invention and production of nonstandard fasteners.

I guess a few engineers at Ford, GM, and Chrysler, not to mention a few bastards at VAG will have to find a new line of work besides inventing wild strange new types of fasteners no one needed or asked for.

And while I'm at it, I'll order the ******* who invented triple square to be hunted down and prosecuted for mechanical crimes against humanity.

 

[Tuc04]

Suncast plastic storage sheds use 9mm for the plastic screws. They also use a really odd metric thread that I couldn’t find anywhere.

 

[Ign]

Yup. When I am King of the World, I will immediately outlaw the invention and production of nonstandard fasteners.

I guess a few engineers at Ford, GM, and Chrysler, not to mention a few bastards at VAG will have to find a new line of work besides inventing wild strange new types of fasteners no one needed or asked for.

And while I'm at it, I'll order the ******* who invented triple square to be hunted down and prosecuted for mechanical crimes against humanity.

The best I heard was when Lotek called it "******* on the engineering tree." Basically some insecure engineer feels he can have a bit of immortality by designing a completely unnecessary fastener that doesn't work any better than what's already out there and causes us all to hate him.

Once Ford finally abandoned TTB in '96/7 they had to send those engineers somewhere....along with Team TFI. Some of them designed the serpentine routing on the modular motors GM also had to employ Team-Steering-Box-Tears-Itself-from-the-Frame.....and Chrysler had to do something with those K-car guys

If that's the kinda legacy you want to leave behind....

 

[2ndGearRubber]

Yup. When I am King of the World, I will immediately outlaw the invention and production of nonstandard fasteners.

I guess a few engineers at Ford, GM, and Chrysler, not to mention a few bastards at VAG will have to find a new line of work besides inventing wild strange new types of fasteners no one needed or asked for.

And while I'm at it, I'll order the ******* who invented triple square to be hunted down and prosecuted for mechanical crimes against humanity.

That, and sticking with the CORRECT sizes for their brands. I'm seeing nissans with 13mm and 18mm now. Not allowed, IMO. It's like a 17mm on a GM, or a 15 on a honda.

 

[American Locomotive]

That, and sticking with the CORRECT sizes for their brands. I'm seeing nissans with 13mm and 18mm now. Not allowed, IMO. It's like a 17mm on a GM, or a 15 on a honda.

That's the Renault leaking into Nissan's engineering.