Nuts and bolts. SAE, Metric, or both

[T18skyguy]

I been wrenching on vehicles all my life. It use to be only SAE, then it became a mix of SAE and Metric. I thought they we're going to phase out SAE and go all metric at some point, but it seems like it's been a mix forever. I'm putting together a tool kit for my 2017 Greyhawk. Do I still need both SAE and Metric wrench and sockets? Are they ever going to switch over to all metric and be done with it? Tools are heavy I just wish there could be one standard.

[ktmrfs]

time2roll wrote:
What bugs me is the imports long used 10, 12, 14, 17mm wrenches and the US factories went metric with 9, 11, 13, 15, 19 mm. Seems like a conspiracy of the tool makers. So it is like we need three sets now.

what I've found is many japanese cars use the 10/12,14 etc. while the european cars use the 9, 11,13, 15, etc.

in the 60's it was even worse. the japanese metric thread pitches didn't always match european metric thread pitch. now at least there are only two thread pitches/size similar to the SAE Fine and course system.

[ktmrfs]

Big Katuna wrote:
Metric may not be better but it’s way easier for most people to add 25mm and 12mm than “1-5/16 and “7/8.

exactly. it isn't that one is "more accurate" than the other, (it isn't) it's that the metric system is much easier to do the math.

and have the units come out in a standard format and one base measurement unit. No do you want inches/ft/yards,miles or ounces/lbs etc.

and that many conversions are real easy.

No 8lbs/gallon 16 oz/lb, 12 inches/ft 3ft/yard ****

1 liter of water (1000cc) = 1KG, (1000g) 1 cu meter=1000KG ("metric ton)

same with distance. easy to calculate



and when you get to complex physics problems it makes the world much easier.

[Chum_lee]

liborko wrote:
If it was so easy to design perfect system right from the start we would not have imperial system, bias ply tires, beta vs VHS, 4x8 sheets of plywood, 2x4 lumber, NTSC vs PAL vs SECAM, 120V/60Hz vs 220V/50Hz etc. You can go on and on. Things evolve. It is called progress. The thing is to recognize what is better and adjust accordingly.

It's not really about better, it's just sneaky business on a grand scale which the general public doesn't understand.

It's a game that manufacturers play with each other to bid/win large scale contracts. Imagine if you were Boeing and bidding on the next MASSIVE government defense contract. At the last minute prior to bid, you get the design team to specify something as a "HAS TO" be built to SAE standards (or some other project parameter) for whatever "apparently good" reason. Your competitors are all metric and would have to redesign/retool to meet the project specifications. What happens next? Boeing wins the bid and everything still looks copacetic. It happens all the time. I know because I used to have a hand in it. That's why there are $2500 toilet seats and $1500 hammers that otherwise look . . . . normal. It's all about money.

Chum lee

[liborko]

If it was so easy to design perfect system right from the start we would not have imperial system, bias ply tires, beta vs VHS, 4x8 sheets of plywood, 2x4 lumber, NTSC vs PAL vs SECAM, 120V/60Hz vs 220V/50Hz etc. You can go on and on. Things evolve. It is called progress. The thing is to recognize what is better and adjust accordingly.

[time2roll]

mike-s wrote:

time2roll wrote:
What bugs me is the imports long used 10, 12, 14, 17mm wrenches and the US factories went metric with 9, 11, 13, 15, 19 mm. Seems like a conspiracy of the tool makers. So it is like we need three sets now.

The standard ISO/ANSI sequence is
7, 8, 10, 13, 16, 18, 21, 24, 30
DIN (Germany) is
7, 8, 10, 11, 13, 17, 19, 22, 24, 27, 30
JIS (Japan) is
7, 8, 10, 12, 14, 17, 19, 22

So, much depends on what you're working on, even the age. Old VWs commonly used 10, 13, 15, 17, 19, 21. Newer ones started using 16 and 18. I had never used a 12 until my wife got a Toyota.

OK my numbers were off a bit.
Still if you want a full set you have to buy every number from 6mm to 30mm just in case. And a few will never be used and just take up space. Wrenches(long and short), deep/short sockets, 6pt/12pt, crow feet.... tool for every possibility is exponential.

And if the set is truly metric why are all the ratchets and extensions 1/4, 3/8, 1/2 (etc) inch drive. I am so happy I am long out of the business of turning wrenches.

[fj12ryder]

Well, even the Japanese motorcycle industry couldn't decide which sizes to use. Honda used mostly even numbers 10,12,14, but Suzuki and Yamaha used more odd numbered 11,13,15. Go figure.

[mike-s]

time2roll wrote:
What bugs me is the imports long used 10, 12, 14, 17mm wrenches and the US factories went metric with 9, 11, 13, 15, 19 mm. Seems like a conspiracy of the tool makers. So it is like we need three sets now.

The standard ISO/ANSI sequence is
7, 8, 10, 13, 16, 18, 21, 24, 30
DIN (Germany) is
7, 8, 10, 11, 13, 17, 19, 22, 24, 27, 30
JIS (Japan) is
7, 8, 10, 12, 14, 17, 19, 22

So, much depends on what you're working on, even the age. Old VWs commonly used 10, 13, 15, 17, 19, 21. Newer ones started using 16 and 18. I had never used a 12 until my wife got a Toyota.

[JohninSD]

I carry a Metrinch tool set, have had it for 20 years or so, fits SAE and Metric. Still available from Amazon but at a higher price than I remember paying. If I can't fix whatever's broken with this and a few allen wrenches, screwdrivers, pliers, etc. I take it to a shop - well except for the house part of the RV of course - there don't seem to be any competent, honest, available in less than a few months RV repair facilities.

[time2roll]

What bugs me is the imports long used 10, 12, 14, 17mm wrenches and the US factories went metric with 9, 11, 13, 15, 19 mm. Seems like a conspiracy of the tool makers. So it is like we need three sets now.

[liborko]

There must be a reason why most of the world adopted metric system, including UK, South Africa, New Zealand, Canada and Australia. Metric system uses 7 basic units for measurement in science, engineering, industry and commerce and all the rest of units are derived from these basic units. Imperial system uses 56 basic units.
The beauty of metric system is the use of multiples of ten, hundred, thousand etc. with metric multipliers like micro, milli, centi, deci, deca, hecto, kilo, mega, giga, tera etc.
For example one metric ton is 1000kg, one kilogram(kg) is 1000g(gram)
In metric system you are dealing with whole numbers instead of fractions. I will take metric system anytime.
Definition of basic metric units were fine tuned over the years mainly to facilitate verification of standards by any country any time.

[Big_Katuna]

I’ve redone quite a few properties and use helpers and I still don’t understand how so many can’t read a tape measure, much less add basic measurements.

[fj12ryder]

Big Katuna wrote:
Metric may not be better but it’s way easier for most people to add 25mm and 12mm than “1-5/16 and “7/8.

No argument there, but most machinists and good mechanics worth a **** work with decimals. So that 1-5/16" becomes 1.0625, and 7/8" becomes .875, which is as easy to add as metric.

[MEXICOWANDERER]

Hell anymore I have to do it by Braille. I love how the Chinese used No 2 font on their sockets, and scratch marks on the wrenches.

[Big_Katuna]

Metric may not be better but it’s way easier for most people to add 25mm and 12mm than “1-5/16 and “7/8.