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Changing Socket Sizes

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Leaflessshadetree

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I know I use a T-27 on Harley Davidson final drive cover. Seems like I use it other places as well. I've heard it is an elusive size in tool sets, but most of mine seem to have it.
 

metaleltr

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GM uses t27, but gm has been know to use special torx before-seatbelts for example,

Any chrysler gurus know if they use t27? I know chrysler loves their torx screws
 

Matt_C

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I've used T27 on German stuff (VW and BMW, and maybe a Merc), but I don't remember if I've seen one on a Chrysler
 

PBCampbell

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German OPE manufacturers like Stihl and Dolmar like T27. I can't say I've encountered that size anywhere else.
 

djb2

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I think he's asking what industry standard specifies using T27. It does seem like it's an intentionally odd size, when T25 or T30 would work just as well.

I don't understand the motivation behind ISO-4017. 17mm was widely used, and most tool sets skipped 16mm and 18mm. I could understand if they only suggested 16mm, which is pretty much 5/8" and thus a good choice for global equipment. But specifying 18mm they made it clear they were (like a few other ISO standards) trying to screw over everyone equally.

BTW, this is exactly the shenanigans that makes metric a worse choice than SAE sizes. It's not more logical. It's just different.

Torx and E-Torx were specifically designed to not map to metric or SAE sizes so that it wouldn't be part of the conflict.
 
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RCStocker

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I have use T27 on Chevy tucks and once on a Ford Crown Victoria.
I have no idea way companies skip sizes. I hate that and will never buy sets that skip. I don't even buy them used. HF impact sockets are very good. I have Snap-on and other brands but have never had a HF fail. they sip sizes and don't sell the missing sizes.

I am anile and hate missing anything. LOL My Town car and crown Victoria take a 16mm on the oil pan. some sets skip the 16mm.

I sold my nice Craftsman stubby wrenches because they did not make the missing sizes. I have them in Gearwrench and now SK and Snap-on You save nothing if you need to buy the missing ones then the set does not match. If you buy used it cost more to fill in the set than buying a complete set.

Pox on skipping. I know they do it to keep the price down but they cut their own head off. LOL I would have gotten all HF impacts for my sons and grand sons. I was not going to give them sets with missing items no mater how good the quality. I went with SK sets for everyone. You can get them at great prices used or new with huge discounts. Best bang for the buck.

We need to put out Amber alerts for sets with missing pieces. LOL
 

jjjrmx5

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BTW, this is exactly the shenanigans that makes metric a worse choice than SAE sizes. It's not more logical. It's just different.

No.

The M size and pitch does not change. Just the head size.
That's why they make different sized wrenches/sockets.

Need an M6x1.00 but have a small drop hole due to casting or interferences? Then yep, it's not a ZOMG WTF std. size head bolt. Threads and pitch are ...uhh...still the same. I see it occasionally.


It happens. More than ya think.

Torx Plus pisses me off more than anything because Torx let the patent run out and the Plus played into hands of those with money and tooling. And influence.

As for T27, yep. I see it sometimes.
Mfgrs are mfrs and tools are tools. Engineers spec it and mfgrs build it.
***** at them, not the bolts. The fasteners meet the standards, but obviously don't appease the tool buying public.

And I continue to LOL at that. My wallet on the other hand , is still not so happy so thus I agree. :)
 

crewchief888

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seems like jeep uses t27 on windshield or mirror mounts....


it's gotta be why i have a nearly new T27 SO gold bit.... :dunno:



:beer:
 

92integra

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To op Adam c. I'm guessing you probably know already but in case you don't the snap on low profile 3/8ths sockets don't come with a 19 mm in the set but they do make it in that size as well as 15mm and 9 mm if u need to fill a tray! :beer:
 

n8n

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But I do think it is interesting to see Snap On producing sets of metric sockets missing the 19mm.

Really? that makes no sense at all. That was one of my most used wrenches/sockets even years ago when I first started working on German cars, along with 10, 13, 17. Producing a set without a common size seems silly to me. (it still seems odd to me to use a 12, 14, 16, or 18mm wrench... but I have them because they show up)
 

AndrewV

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T27 is also used by ford for some of the plastic undercarage covers.
Everyone else has them listerd, so there's my contrabution.
 

-Z-

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For example: In the past German cars followed the DIN 933 std, most important sizes were 8, 10, 13,17, and 19mm. Japanese cars followed the JIS B 1180 (for the same sizes of bolts) head sizes were 8,10,12,14,and 17mm. Both specs have changed in the last 10 years or less to fall in line with the ISO 4017 std which is 8,10,13,16,and 18mm for M6, M8, M10, and M12 bolts.

So Japenese motorcycles, past 10 years: no longer with 12, 14, 17, replaced with 13, 16, 18? Is that correct?
 

Elvenhome21

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I would bet the reason they skip 16mm is that they make a 5/8" in SAE and once you figure in their manufacturing tolerances there is no significant difference between the two.

I dont recall ever being able to use a 16mm on a 5/8. But 13 and 14mm are almost identical to 1/2 and 9/16, so in my tool belt at work I leave out 1/2 and 9/16 on my wrench caribener because they cross over with metric and the metrics are a hair snugger on the nuts then sae.
 

sberry

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Hey thanks- I didn't know that. I've never used the low pro tools before. This is good to know.

In case you are wondering, my thinking is that the std sockets, while still useful, are growing less so. I am investing more in (what I call) specialty tools. I bought a set of swivel sockets, love them. I have a mixed set of XDHR wrenches. I recently picked up some stubby triple squares, ball allens etc.

No longer is a wobble extension and flex head ratchet going to save me. This thread is my attempt to determine which sizes I really will need moving forward as these specialty tools don't come in comprehensive sets and can be quite expensive. I don't have 12 or 14mm XDHR wrenches for example. Will I need them? Probably not forever is what I'm learning. And while I haven't come across 16 or 18mm bolts yet, I probably will soon.
Adam.C is offline Report Post
You can way over think this too and prepare for a lot of stuff that never happens. If I need a new tool it will be only a few, I saw the changes with different mfg, the 9/16 hasn't become obsolete yet but for specialty cases. I have Sears 16 and 18 and need it on occasion, still need duplicate of the many standards, a handful of those sizes get buy and use a common combo a hundred to one over some pricey set I might need one or 2 of.
 
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sberry

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This isn't for collectors but for new guys,, I bought a 16 6 pt as a single, at the time the auto store was SK and I paid about 8 dollars delivered for a job, either I couldn't find mine or only has 12, it was on a truck I owned. Havnt really need it specifically and that need didn't drive a compulsion to gather every one size and shape they invented just in case.

Thanks to Adam for the work on bolt sizing, I would like to see some on the concept of proper lubricated threads. I got to see some ( ideas from Adam) on a truck I bought, French Mack. Slightly different design, French. English and German and some good QC during original assemply in regards to fasteners.
As first it "looked" like it would be a real battle but not actually so all things considering. (a lot of minor details I don't feel like typing now though).
 

shockwave

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It's weird that this post has come up I just replaced a blown engine on a 2008 Nissan sentra and it was filled with 13mm,16,and 18mm I was surprised to see this as most japanese standards are 12,14 17 and 19
 

abvw

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It's weird that this post has come up I just replaced a blown engine on a 2008 Nissan sentra and it was filled with 13mm,16,and 18mm I was surprised to see this as most japanese standards are 12,14 17 and 19

I was also quite confuzzled when 16mm and 18mm were used in the newer Civic's suspensions.

Is there a way to distinguish between JIS, DIN and ISO? Like maybe a hood sticker or what not? That will sure cut down the trips to the box..
 

sselander

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Here is one chart that clearly shows what Adam is talking about:

Metric Bolt Head/Wrench Size
http://www.boltdepot.com/fastener-information/bolts/metric-bolt-head-size.aspx
----------------------------------------------------------
The Industrial Fasteners Institute has some good papers on this topic as well
http://www.indfast.org/info/free-technical-info.asp

Here are the direct links for 2 of them:

Why ISO Standards Should Be Preferred For Metric Fasteners?

ISO Fastener Standards Should Be Referenced
for All Metric Fasteners


Interesting to read that "Germany withdraws DIN standards in 2001 to adopt ISO fastener standards"
 
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sberry

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I think and I wil use the term,,, "they" as a generic but washer under turned element with light oil is as ideal as it cahn. I think one of the reasons for dry lug values is they had to pick one or the other and couldnt get all the chimps to learn to oil the bolts proper,,,,, partly do to so many in these trades with no formal education, learned hand to mouth as evidenced by zillion stuck bolts from amateurs turned loose at tires stores with air guns.
I agree also the real world is different than factory new, clean and often coated fasteners.
As I mention before, this is nothing new, lots of this really went full scale in WW11 and after but Snapon wrench manual says values are for clean lightly lubed.,,,,,,,,,,,,,,,,,,,,,,,,They didn't list other options.

John Deere has a training manual for starting techs that all with a wrench should be forced to read describes the nature of threaded fasteners in simple terms, pretty much boils down to is oiled bolt doesn't stick. Most torque values are only so so but stuck and not turning or providing tension is a deal killer.
 

sberry

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All of this assumes the installer does all this correct.
I got a cuz that is on a Ford line I think, says the under over torque values on the tools will shut the whole line down. Said certain bolts will allow for back ou and tr4y again but lots of suspension comes with encapsulated Locktight. This is as much as an assembly lube for threads as a thread locker.
 

shockwave

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It's weird that this post has come up I just replaced a blown engine on a 2008 Nissan sentra and it was filled with 13mm,16,and 18mm I was surprised to see this as most japanese standards are 12,14 17 and 19

Not really that I know of it would be easier just to take a few sockets and see which ones fit before u break it down
 

bwringer

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T27 is very, very common on chain saws, weed whackers, leaf blowers, snow throwers, etc. No idea why. It comes up often enough for me, especially during the summer, that I keep a cheapo driver loaded up with a T27 at all times.


All this talk of torques, standards, and such is nice, but what I'd really like to see is a standard where equipment is required to be serviceable -- fasteners must be accessible to mechanics who aren't Hobbits, and the driver or socket sizes must be sufficient to actually remove said fastener after two ISO standard Michigan winters (for manufacturers in warm climates, one M.W. is roughly equivalent to submersion in a shallow saltwater tropical lagoon for 6 months).

Furthermore, any manufacturer (I'm looking at YOU, GM...) that decides to make up an entire new type of fastener for no reason whatsoever MUST include a socket or driver that fits it with the sale of each new car, and provide it at no cost to subsequent owners.

Boy, things sure will change when I'm King of the World...
 
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MN Falcon

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I know I use a T-27 on Harley Davidson final drive cover. Seems like I use it other places as well. I've heard it is an elusive size in tool sets, but most of mine seem to have it.

I ran into this one as well. My Craftsman set didn't have the T27 so I ran to Sears and they had none on the wall. They call another Sears which said they had it so I ran across town but they didn't actually have it. Since I was on that side of town I stopped into a hardware store that I have bought some Proto tools from in the past and they had it for only a buck more than Sears had theirs listed for.
 

NFH2740

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I wish metric sets would go through 32 mm. Most stop at 24, yet I need 30 and 32 for my equipment.
 

purplezr2

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GM uses t27, but gm has been know to use special torx before-seatbelts for example,

Any chrysler gurus know if they use t27? I know chrysler loves their torx screws

VW uses T27 for ****** pans, almost sure these are M6 bolts, maybe M5
Polaris uses them to hold plastics on. Not sure what the thread pitch is on these.
Not as uncommon as they once were.
 

Wakefield

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Just responding to my own question; My current belief is that T27 and T47 are non standard Torx head sizes used for 1/4-20 and 3/8" screws. The non std heads help us distinguish them from their metric counter parts (M5 and M10). I can't confirm and haven't found a spec as yet, so if anyone can check this, I'd appreciate it.

My guess is the US auto industry asked for them to make use of new automated installation tools that work best with torx heads for legacy SAE components.
I suspect T 47 was a sort of forerunner of Torx Plus and might have been called a special variation of T 50 at first-confusing listings in the Snap On catalogs around 1980 the shape of my T 47s look more like Torx Plus than the other Torx
 

Schurkey

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Thank you so much for the explanation of JIC, DIN, and ISO bolt head sizes and the "logic" behind them. I was directed here from my own thread about the uselessness of some metric wrench and socket sizes. I never work on European stuff; and no modern Asian stuff. No snowmobiles, no chain-saws. Therefore, 9, 11, and 16 mm tools are entirely useless to me. There may come a day when that changes.


My current belief is that T27 and T47 are non standard Torx head sizes used for 1/4-20 and 3/8" screws.
Be VERY CAREFUL with T47.

There's at least two wrenching forms that are similar enough to interchange tools--until the torque load goes up.

Older GM cars had the door strikers (and maybe seat-belt bolts) installed with a (superficially) Torx-looking tool, but on closer examination it's absolutely not a rounded Torx form. (It may be designed by Textron, Snappy uses the Torx trademark for this tool...but it's not the rounded style that became popular later.)

The Snap-On number for this older not-quite-Torx driver is GFTX500E, while the replacement bit itself is GFTX500E2

http://store.snapon.com/TORX-174-Sp...TORX-174-GM-Style-Industrial-T47-P631940.aspx
GFTX500E.jpg


I am not aware of any other company selling a competing tool.



The second form of this is more rounded like we expect Torx to be. Snap-On p/n FTX47E, with a replacement bit FTX47E2

http://store.snapon.com/TORX-174-Sp...ket-Driver-TORX-174-GM-Style-T47-P636916.aspx
FTX47E.jpg
 
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Wakefield

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I have a "T-47 USA" that came in a set of "MAGNA" that is silvery plated 3/8" drive and one piece--I think it was ordered from a Kent-Moore catalog.
Interesting about the Snap On--so the newer FTX47E is not exact equivalent or exact replacement for the (G)FTX500E

the shiny one piece T-47 has rounded outer edge like the second Snap On in the pictures (post 44) (edit) looked at my Snappy it is FTX500 with no E and the driver part is chromed
 
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dnschmidt

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19mm is almost exactly 3/4". I've never understood why some mixed socket sets, those including both metric and SAE often include both. They are entirely interchangeable. I've never met a 3/4" hex that the slightly smaller 0.74803" 19mm would not fit.
 

toolmutt

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Terrific explanations from everyone, especially Adam. So I take two things from all of this:

1. A headache. :bounce:
2. That if I don't work on a narrow spectrum of equipment (i.e. a specific make of vehicle, etc.) but may need to disassemble/assemble anything from anywhere, then I need every size socket and wrench available. Thanks for confirming my OCD needs. :bounce::bounce::bounce::bounce:
 

Lassen Forge

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I was told that GM used that oddball pseudotorx fastener as a security thing so people wouldn't be able to remove and/or replace seat belts & shoulder harnesses with cheaper (untested and/or lighter) webbing material... or remove them altogether... and when removed/replaced they would take whatever the torque value they specified was.

You could still go to your local NoB partshouse (Napa or Better) and buy one... but it wasn't a common thing for joe homeowner to have.
 

90zcar

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Subscribed....now I need to check which t47 I have. For some reason I think mine are more rounded edges


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