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Metric bolts


Gearclash
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Ah, metric; the system that was supposed to usher in utopia.  Also the only system of measuring that can give you no less than three different hex sizes for one common (10mm) bolt diameter.  Can be 15,16, or 17mm drive.  WONDERFUL!  So if I ruin a metric 10mm bolt on a machine, the odds are the replacement will be a different drive size so now I have an oddball size in the assembly.  😡

Yes I am feeling a bit sardonic today.

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2 hours ago, Gearclash said:

Ah, metric; the system that was supposed to usher in utopia.  Also the only system of measuring that can give you no less than three different hex sizes for one common (10mm) bolt diameter.  Can be 15,16, or 17mm drive.  WONDERFUL!  So if I ruin a metric 10mm bolt on a machine, the odds are the replacement will be a different drive size so now I have an oddball size in the assembly.  😡

Yes I am feeling a bit sardonic today.

Don't forget your choice of about four thread pitches for that same bolt

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2 hours ago, ihrondiesel said:

Add to that the 2 or 3 different thread pitches for the same size bolt. 

 

Just now, Ian Beale said:

Don't forget your choice of about four thread pitches for that same bolt

Yes, another sore point. 
 

There are threaded holes in the bottom of the transmission housing of the legacy CIH Maxxum tractors that are oh so handy for bolting splitting stands to the case. One tiny problem. They are an obscure metric thread pitch. When I needed such a bolt I was able to find that diameter and pitch at  exactly ONE supplier in the whole US. 
 

I suppose it could have been worse . . .  they could have been Whitworth . . . 

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8 minutes ago, Ian Beale said:

The BIG TRAP with Whitworth and NC is half inch - Whitworth 12 tpi, NC 13 tpi.  And you won't make them interchange!

I happen to have personal experience with that -- and recently.  I have a lathe built in the early 70s in some then iron curtain country of eastern Europe.  No doubt all metric EXCEPT the leveling bolts.  Scratched my head for the longest time trying to figure out what they were.  1/2 inch WHITWORTH.  Whiskey - etc, etc.  

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7 minutes ago, Gearclash said:

I happen to have personal experience with that -- and recently.  I have a lathe built in the early 70s in some then iron curtain country of eastern Europe.  No doubt all metric EXCEPT the leveling bolts.  Scratched my head for the longest time trying to figure out what they were.  1/2 inch WHITWORTH.  Whiskey - etc, etc.  

Then there is 3/8" NC and 10 mm metric coarse.  I've discovered that the exhaust manifold bolt holes on our Fiat Allis 10 have been helicoiled  - with 3/8 NC.

One is now back to 10 mm because I "cleaned the thread" with a 10 mm tap and that is how I found it had a helicoil in it.

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Well, we in fractional inch land usually only have two thread pitches and, with metric there's only two common but yes there's one more PITA pitch. Interestingly in the rest of the world fractions are pretty much unknown other than what would be on a gas gauge.

It sure would have been nice if we could have gotten on the metric system as it really is easier, it's just hard to accept changes and frustrating too. I just roll with it and keep my metric tool box next to my inch box. I just wonder where my 10mm sockets go. Actually, after retrieving some from my window sill, cup holders, lift arms and jacket pockets I now have a surplus of them but they'll start to walk soon.

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4 hours ago, Farmall 1466 said:

I'm amazed, I've never seen anything other than a 17mm drive on a 10mm bolt. Same with 12mm bolt, only 19mm drive, but I'm from Europe. Maybe it has to do with adapting the metric diameter bolt to your imperial drives?

I think metric bolts can be made to  DIN, JIS and SAE standards, all a little different.  

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9 minutes ago, New Englander said:

Well, we in fractional inch land usually only have two thread pitches and, with metric there's only two common but yes there's one more PITA pitch. Interestingly in the rest of the world fractions are pretty much unknown other than what would be on a gas gauge.

It sure would have been nice if we could have gotten on the metric system as it really is easier, it's just hard to accept changes and frustrating too. I just roll with it and keep my metric tool box next to my inch box. I just wonder where my 10mm sockets go. Actually, after retrieving some from my window sill, cup holders, lift arms and jacket pockets I now have a surplus of them but they'll start to walk soon.

My 10mm sockets got to the same place that 1/2in wrenches go. Somewhere far away from where I need them.

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7 minutes ago, 12_Guy said:

Not to be stirring up the hornet's nest here, but you fellas do realize that we Americans have two different thread pitches and heavy nuts and standard nuts of the same bolt size.

Seems to me that you guys may need something better to complain about. 

Farmer always like to grumble about something 😉 with the right pushes this could become a oil thread.😄 As the snow is falling in places already we need a good waster of time.🤣

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At one time we had many different thread systems before the Unified system came out 

Stuff built before 1900 is likely to have manufacture specific thread pitches 

I worked at Brown & Sharpe they started building machine tools at the start of the industrial revolution and had their own thread system

They made cutting tools too so they made their own taps and dies  

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Anyone who has worked on a Farmall H has to admit frustration with them. Harvester used Course thread, fine thread, Heavy nuts, extra thin nuts, square bolts and list goes on. 

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4 hours ago, Gearclash said:

I happen to have personal experience with that -- and recently.  I have a lathe built in the early 70s in some then iron curtain country of eastern Europe.  No doubt all metric EXCEPT the leveling bolts.  Scratched my head for the longest time trying to figure out what they were.  1/2 inch WHITWORTH.  Whiskey - etc, etc.  

The hydraulic system on our FA 10 dozer was mostly well farmerised, with a few mystery original fittings left.  They didn't fit anything metric.  Turns out that the originals were BSP and that was common in European equipment of the era.

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...talking of hydralic  threads......Komatsu have their own   fittings which have a ''pucker factor''  when dealing with hose doctors  via the white mans magic..on a weekend call requirement....

so near ..but so far in reality

Mike

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2 hours ago, 12_Guy said:

Not to be stirring up the hornet's nest here, but you fellas do realize that we Americans have two different thread pitches and heavy nuts and standard nuts of the same bolt size.

Seems to me that you guys may need something better to complain about. 

Generally the odd ball inch stuff stays off in the dark corners where it belongs rather than turning repair work on common place machines into a what-size-is-it-this-time guessing game.  Metric is so pitifully inconsistent.  If person A worked exclusively on CNH products and person B on exclusively Honda products, each would have about 1/3 of their wrenches and sockets they would never use.  And it would be different sizes.  10mm drive on a 6mm bolt is about the only thing they can agree on.

 

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I concluded long ago that the only winner from the proliferation of metric in the US has been the tool companies. They get to sell us twice the number of tools, not to mention bigger tool boxes to hold them all.

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There’s no doubt that if the engineers that design equipment had to work on it they would design it simpler to work on. Pto shafts are my pet peeve right up there with metric anything. Why can’t they put zerks  where you can see them? Seems like they are more and more in a darn hole where once you put your grease gun in there you can’t see a thing til you take it out and realize you wasn’t getting grease in the zerk

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15 hours ago, Gearclash said:

 

Yes, another sore point. 
 

There are threaded holes in the bottom of the transmission housing of the legacy CIH Maxxum tractors that are oh so handy for bolting splitting stands to the case. One tiny problem. They are an obscure metric thread pitch. When I needed such a bolt I was able to find that diameter and pitch at  exactly ONE supplier in the whole US. 
 

I suppose it could have been worse . . .  they could have been Whitworth . . . 

Bolted the steering stabilizer back onto m 95 range rover front differential that the previous owner had removed... 

My first run in with whitworth,   

Whitworth 1,  Me 0

Unsure when the next rematch will be,  but who can ever be totally sure when these things happen???

 

PS

"sardonic"

Thats a new word for me,  Looked it up,  i feel like alot of the time when i was being sarcastic i was being sardonic and I didnt even know!  #Gamechanger!

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