Reply
 
Thread Tools Display Modes
  #1  
Old 05-13-2020, 08:42 AM
Paul in Qatar is offline
Guest
 
Join Date: Jul 2002
Location: Dammam, Saudi Arabia
Posts: 13,447

Was There a Scale of Measurements Based on Tenths of Inches?


As a child I recall being told Henry Ford, that nut, developed the "Ford Scale" that used parts (and so tools) based on tenths of an inch. (No quarter inch nuts, but you could have 2/10 or 3/10.)

A Google turns up nothing. Was I lied to?
__________________
800-237-5055
Shrine Hospitals for Children (North America)
Never any fee
Do you know a child in need?
  #2  
Old 05-13-2020, 08:47 AM
CalMeacham's Avatar
CalMeacham is offline
Charter Member
 
Join Date: May 2000
Location: Massachusetts
Posts: 45,600
Quote:
Originally Posted by Paul in Qatar View Post
As a child I recall being told Henry Ford, that nut, developed the "Ford Scale" that used parts (and so tools) based on tenths of an inch. (No quarter inch nuts, but you could have 2/10 or 3/10.)

A Google turns up nothing. Was I lied to?
I've never heard of a "Ford Scale", but people do use tenths of inches -- I've seen rulers scaled in tenths of an inch rather than the more traditions 1/16", 1/8", 1/4", and 1/2" divisions.

And, of course, machinists routinely use decimal fractions of an inch, and characterize uncertainties measured in thousandths of an inch.

Tenths of an inch ruler:

https://www.amazon.com/Tenths-Ruler-.../dp/B003G5CLZS
__________________
The makers of the GoPro have to come out with a model called the "Quid"

Last edited by CalMeacham; 05-13-2020 at 08:49 AM.
  #3  
Old 05-13-2020, 09:05 AM
Edward The Head is offline
Charter Member
 
Join Date: Jun 2000
Location: Somewhere in time
Posts: 6,634
You can get an engineering ruler, it has six different scales on it, 10, 20, 30, 40, 50, and 60 of an inch. I don't use them any more, but I have a couple at the office. Our CAD programs will also do most things in tenths of an inch.
  #4  
Old 05-13-2020, 09:08 AM
beowulff's Avatar
beowulff is offline
Member
 
Join Date: May 2001
Location: Scottsdale, more-or-less
Posts: 17,436
Printed circuit board layout commonly uses .1” and .001” grids.
  #5  
Old 05-13-2020, 09:22 AM
Paul in Qatar is offline
Guest
 
Join Date: Jul 2002
Location: Dammam, Saudi Arabia
Posts: 13,447
Quote:
Originally Posted by beowulff View Post
Printed circuit board layout commonly uses .1” and .001” grids.
A "mil"is 1/1,000 of a inch and is not uncommon. As you say, it is used on circuit boards, but also in some measurements of paper thickness.


But in this case, I was told you needed special tools to work on old Fords, as well as parts (nuts & bolts) only Ford produced.
__________________
800-237-5055
Shrine Hospitals for Children (North America)
Never any fee
Do you know a child in need?

Last edited by Paul in Qatar; 05-13-2020 at 09:23 AM. Reason: ...
  #6  
Old 05-13-2020, 10:19 AM
What Exit?'s Avatar
What Exit? is offline
Member
 
Join Date: Jun 2005
Location: Central NJ (near Bree)
Posts: 30,311
I've used and still own some Engineering scales (tri-edged rulers). As mentioned above they us 1/10 scales. I also use to use 1/10th inch graph paper for almost everything that needed graph paper.
https://en.wikipedia.org/wiki/Scale_ruler has some pictures.
  #7  
Old 05-13-2020, 10:21 AM
crowmanyclouds's Avatar
crowmanyclouds is offline
Guest
 
Join Date: Sep 2005
Location: ... hiding in my room ...
Posts: 5,080
Quote:
Originally Posted by Paul in Qatar View Post
{...} But in this case, I was told you needed special tools to work on old Fords, as well as parts (nuts & bolts) only Ford produced.
You're not thinking of Ford's short use of Robertson (AKA square drive) screws are you?

CMC fnord!
  #8  
Old 05-13-2020, 10:34 AM
Paul in Qatar is offline
Guest
 
Join Date: Jul 2002
Location: Dammam, Saudi Arabia
Posts: 13,447
Quote:
Originally Posted by crowmanyclouds View Post
You're not thinking of Ford's short use of Robertson (AKA square drive) screws are you?

CMC fnord!
Well, it was long ago and on the edge of memory. I appreciate your link, but in my mind's eye I imagined nuts, bolts, and spanners. Funny how little half-memories get stuck in your head.
__________________
800-237-5055
Shrine Hospitals for Children (North America)
Never any fee
Do you know a child in need?
  #9  
Old 05-13-2020, 10:39 AM
Paul in Qatar is offline
Guest
 
Join Date: Jul 2002
Location: Dammam, Saudi Arabia
Posts: 13,447
My goodness, I just read up on Mr. Robertson's wonderful screws. It seems Ford widely used them in the Good Old Days. Yes, I am pretty sure that is the truth that somehow got twisted in the telling. Thank you all.
__________________
800-237-5055
Shrine Hospitals for Children (North America)
Never any fee
Do you know a child in need?
  #10  
Old 05-13-2020, 01:04 PM
Chronos's Avatar
Chronos is offline
Charter Member
Moderator
 
Join Date: Jan 2000
Location: The Land of Cleves
Posts: 88,635
Once, in an instructional lab I was teaching, one group kept getting answers a little bit off and we couldn't figure out why, until we finally noticed that they were using a ruler that was marked in 32nds of a foot, instead of centimeters.
  #11  
Old 05-13-2020, 06:27 PM
Melbourne is offline
Guest
 
Join Date: Nov 2009
Posts: 6,313
Quote:
Originally Posted by Paul in Qatar View Post
A "mil"is 1/1,000 of a inch and is not uncommon. As you say, it is used on circuit boards, but also in some measurements of paper thickness.


But in this case, I was told you needed special tools to work on old Fords, as well as parts (nuts & bolts) only Ford produced.
There are certainly special parts that you need special tools to work on - trim, oil filters, spark plugs etc.

I've got a vague memory that the very very first Fords had a single suspension or drive nut that was not a standard dimension, but I could be wrong.

A lot of the Ford tools actually have "Ford" written on them, but that's just branding. The original Ford adjustable wrench is sometimes called a "Ford wrench" -- I think that's because adjustable wrenches like that weren't (aren't) very common.

Also, the threads on early bolts and studs won't exactly match modern nuts. The thread profile is different. Sometimes this matters.

Specific question: did Ford ever use 5/10th nuts? Dunno.
  #12  
Old 05-13-2020, 07:18 PM
Horatius is offline
Guest
 
Join Date: Dec 2002
Location: Ottawa, ON
Posts: 1,463
Quote:
Originally Posted by Paul in Qatar View Post
My goodness, I just read up on Mr. Robertson's wonderful screws. It seems Ford widely used them in the Good Old Days. Yes, I am pretty sure that is the truth that somehow got twisted in the telling. Thank you all.


Canadians would love it if they became more wide-spread. I just finished building some frames for a raised bed garden using them. They're way better than most other screws.


As for the OP's question, the Japanese "shaku-sun-bu" measurement system is a powers' of ten system, where a shaku is very close to a foot in length. Of course, the only use I've ever seen of that system is measuring sword lengths, and the naming of the "Shaku-hachi" flute, so named because it is 1 shaku, 8 (hachi) sun in length.
__________________
Where am I going, and why am I in this handbasket?
  #13  
Old 05-13-2020, 07:59 PM
Hampshire is offline
Member
 
Join Date: Jan 2003
Location: Minneapolis
Posts: 11,299
All our manufacturing tooling drawings are spec’d in inches and then decimals after that. So in essence tenths, hundredths, thousandths of an inch. A typical depth may be noted as 1.027 +/-.005
  #14  
Old 05-14-2020, 04:58 AM
bob++ is online now
Guest
 
Join Date: Jan 2013
Location: Worcestershire UK
Posts: 7,153
Quote:
Originally Posted by Hampshire View Post
All our manufacturing tooling drawings are spec’d in inches and then decimals after that. So in essence tenths, hundredths, thousandths of an inch. A typical depth may be noted as 1.027 +/-.005
Only in the USA. Everywhere else uses millimetres.
  #15  
Old 05-14-2020, 07:13 AM
Balthisar is offline
Charter Member
 
Join Date: Nov 2000
Location: Southeast Michigan, USA
Posts: 11,586
Quote:
Originally Posted by bob++ View Post
Only in the USA. Everywhere else uses millimetres.
Canada's a mixed bag, though, and not 100% on the mm train.
  #16  
Old 05-14-2020, 09:22 AM
Yllaria is offline
Charter Member
 
Join Date: Nov 2001
Location: Stockton
Posts: 11,255
Quote:
Originally Posted by Edward The Head View Post
You can get an engineering ruler, it has six different scales on it, 10, 20, 30, 40, 50, and 60 of an inch. I don't use them any more, but I have a couple at the office. Our CAD programs will also do most things in tenths of an inch.
It's a scale thing. If you're working on paper plans where 1"=60', it's easier to grab the 60 ruler with it's adjusted 10ths of an inch, and measure how far that bench is from that planter. On it, one mark's length equals one foot. You don't even have to calculate, the way you would if you had to calculate "well it's 1-7/32nds of an inch, so . . . "
  #17  
Old 05-14-2020, 11:11 PM
Mr Downtown is offline
Chicago Savant
 
Join Date: Jan 2009
Location: Chicago
Posts: 2,542
"Borrowed" at some point from my dad, I have a late 1950s small T-square with one side in 16ths of an inch, and the other side in 10ths. It looks to have been a giveaway promo for General Electric tubes and television components, though I don't know whether that's relevant (maybe tube-era electronic chassis were laid out in 10ths of an inch). Because this was probably the first straightedge or ruler I ever saw, it never occurred to me that it was unusual. But I don't remember ever seeing another ruler showing 10ths of an inch. By the time I was in school, they all had metric on one side—and later, working as a typesetter, they had picas.

Last edited by Mr Downtown; 05-14-2020 at 11:14 PM.
  #18  
Old 05-14-2020, 11:33 PM
friedo's Avatar
friedo is online now
Guest
 
Join Date: May 2000
Location: Las Vegas
Posts: 24,607
Quote:
Originally Posted by beowulff View Post
Printed circuit board layout commonly uses .1” and .001” grids.
What ever do you mean? Everybody knows that DIP pins are spaced exactly 2.54mm apart! No inches to be seen here.
  #19  
Old 05-15-2020, 01:50 PM
bump is offline
Guest
 
Join Date: Jun 2000
Location: Dallas, TX
Posts: 19,673
Surveying is still done in decimal feet (feet & tenths of feet), or at least it was back when I was in college. Makes the math easier.
  #20  
Old 05-17-2020, 04:54 AM
Gary T is offline
Member
 
Join Date: Mar 2002
Location: KCMO
Posts: 11,437
Quote:
Originally Posted by bump View Post
Surveying is still done in decimal feet (feet & tenths of feet), or at least it was back when I was in college. Makes the math easier.
I remember using a transit with a measuring stick graduated in hundredths of a foot. That happens to be very close to eighths of an inch, which is interesting but coincidental.
  #21  
Old 05-17-2020, 04:13 PM
krondys's Avatar
krondys is offline
Member
 
Join Date: Apr 2011
Location: Gillette, Wyoming
Posts: 1,263
Quote:
Originally Posted by bump View Post
Surveying is still done in decimal feet (feet & tenths of feet), or at least it was back when I was in college. Makes the math easier.
Can confirm, still is ('round these parts, anyway).
  #22  
Old 05-17-2020, 05:52 PM
E-DUB's Avatar
E-DUB is offline
Guest
 
Join Date: Mar 2013
Posts: 5,099
I've got a ruler that has 1/10's of an inch on one edge (the other is conventional halves, quarters, etc). One side does say (Faded) Engineering division.

Can't recall where I got it. I use it for scale model work. It makes it easier when a measurement from the prototype comes out as 6.37 inches to just go in on the high end of 6.3 rather than converting to English.
  #23  
Old 05-21-2020, 04:03 PM
Bonum Legatum is offline
Guest
 
Join Date: May 2020
Posts: 2
To the OP: If you go to www.archive.org and search for "shop theory henry ford", one of the responses will be a book titled "Shop Theory by Henry Ford" (and that should be "Shop Theory by the Henry Ford Trade School". Download the book and you will see a decimal ruler on Page Number 35, along with a discussion of how it was to be used.

The decimal system would work well with the very precise and accurate shop measurement system provided by Johansson blocks, manufactured in decimal inches.
  #24  
Old 05-21-2020, 07:55 PM
Some Call Me... Tim is offline
Guest
 
Join Date: May 2000
Posts: 1,888
Centuries before that, Thomas Jefferson's 1790 proposal of a Plan for Establishing Uniformity in the Coinage, Weights, and Measures of the United_States included a decimal system of measure in which a tenth of an Inch would be called a Line. (This wasn't quite the same Inch, though, being 1/10 of what it was using as a Foot)

While the US did adopt its radically innovative decimal coinage system (the 'dollar') based on this proposal, we did not adopt decimal measurements as was recommended. A few years later the French adopted a similar decimal based system of measures, but called it the "metric system"... you might have heard of that one.
  #25  
Old 05-21-2020, 09:46 PM
beowulff's Avatar
beowulff is offline
Member
 
Join Date: May 2001
Location: Scottsdale, more-or-less
Posts: 17,436
Quote:
Originally Posted by friedo View Post
What ever do you mean? Everybody knows that DIP pins are spaced exactly 2.54mm apart! No inches to be seen here.
Reminds me of “Plotter units.”
Whenever I see the number 1016, I am reminded of HPGL, where the original unit was 1/1016 of an inch, or 1/40th of a mm.
  #26  
Old 05-22-2020, 06:48 AM
Xema is offline
Guest
 
Join Date: Mar 2002
Posts: 12,571
Quote:
Originally Posted by Horatius View Post
Canadians would love it if they became more wide-spread.
They [Robertson screws] are great, but now in decline, I believe. Torx fasteners are taking over - they have some advantages, including anti-cam-out.
  #27  
Old 05-22-2020, 07:23 AM
bubba001 is offline
Guest
 
Join Date: Jul 2013
Posts: 310
Ford used Johansson blocks. Now, all these reference blocks are called Jo blocks. They were so prevalent in the Detroit area that I’ve seen Jo block sets with a Ford logo on them, in independent shops, even at Cadillac Motor, a division of GM. Ford might have even bought Johansson. And to a toolmaker, a tenth is 1/ 10000 of a inch. Ford really created the standards, not just set the standards for industry. Not only autos, but aviation and virtually all manufacturing in the world. I had the pleasure of working with a lot of graduates of the Henry Ford trade school. This was to my knowledge, the only Europeon style training school in this country. With that level of training, Ford could do anything.
  #28  
Old 05-22-2020, 10:33 AM
minor7flat5's Avatar
minor7flat5 is offline
Charter Member
 
Join Date: Sep 2002
Location: Trenton, NJ
Posts: 5,111
Quote:
Originally Posted by bob++ View Post
Quote:
Originally Posted by Hampshire View Post
All our manufacturing tooling drawings are spec’d in inches and then decimals after that. So in essence tenths, hundredths, thousandths of an inch. A typical depth may be noted as 1.027 +/-.005
Only in the USA. Everywhere else uses millimetres.
Indeed, though at the level we are talking about the advantage of metric is no longer present--
machinists work in decimal portions of a base unit on both sides of the pond; working in thousandths of an inch or hundredths of a millimeter.

Now, if you want to ridicule the less savory part of imperial units, note how all American machinists intuitively know the fractional sizes in thousandths of an inch--0.1875" is 3/16", for example. So our micrometers have a tiny list of fractional/decimal conversions engraved in the side (example).

A tangent to my tangent: at the inch level, the fractional system is pretty cool in itself because instead of being base-10 like metric, it is base-2: half, quarter, eighth, sixteenth, and so on. That has a certain elegance, until someone tries to mix fractional with decimal.
  #29  
Old 05-22-2020, 02:43 PM
Elendil's Heir is offline
SDSAB
 
Join Date: Jun 2004
Location: 221B Baker St.
Posts: 90,114
What would that be, .067 smoots?: https://en.wikipedia.org/wiki/Smoot
  #30  
Old 05-22-2020, 02:45 PM
Elendil's Heir is offline
SDSAB
 
Join Date: Jun 2004
Location: 221B Baker St.
Posts: 90,114
dp

Last edited by Elendil's Heir; 05-22-2020 at 02:45 PM.
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 06:12 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@straightdope.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Copyright © 2019 STM Reader, LLC.

 
Copyright © 2017