Inch tools
- Thread starter ckucia
- Start date
Mechanical Noise
Well-known member
As far as taps and dies go, the British Empire is generally metric nowadays.
At one time, British taps and dies were normally Whitworth, BSF, CEI, and BA. BA had a metric pitch on a fractional inch rod, if I recall. I guess you could call those FIRST IMPERIAL.
Sometime after WW2, US coarse and US fine threads became common in GB. Those fond of calling such taps and dies Imperial might call them SECOND IMPERIAL.
Of course, THIRD IMPERIAL taps and dies would be metric.
You're gonna need a qualifier if you want the word IMPERIAL to have a specific meaning in the world of taps and dies.
Mechanical Noise
Well-known member
Anyway, what's with the love for the word IMPERIAL? Especially on Independence Day!!
bwringer
Well-known member
Much the same -- I call them "metric" and "inch ****". I have one drawer way in the back for inch **** in case farm machinery shows up, but since I don't work on vintage cars or heavy trucks, and rarely work on Harleys or lawn machinery, it's just not part of my world. YMMV, of course.
"SAE" is widely used to mean "inch ****", but is very much incorrect, since many of the actual SAE standards for fasteners and suchlike include metric. The actual standards published by the Society of Automotive Engineers use the terms "metric" and "inch", since these are the clearest and most accurate words. (You can add the modifier "****" depending on your predilections.)
For example:
J2485_201212: Fastener Part Standard - Machine Screw Nuts (Metric and Inch) - SAE International
This SAE Part Standard covers selected machine screw nuts manufactured in accordance with American Society for Mechanical Engineers (ASME) dimensional standards. This document covers material most often used in ship systems and equipment but its use may be applied wherever nuts of the covered mater
All the above said, I have no idea where the term "imperial" came from or why anyone uses it, but it is another term some people use for some reason. "Inch" is more accurate, and saves two syllables and four letters besides, so I dunno why you'd ever use "imperial".
Bubba Fett
Well-known member
Because it was the standard that most countries used before adopting the metric system.
Mechanical Noise
Well-known member
I still associate SAE tools with cheap K-Mart type sets. SAE and Metric Hey, a 60 piece tool kit for $5! And it's approved by Engineers!! Life is good!!!
It occurs to me that the term IMPERIAL might have been marketing code for tools that were as soft as butter.For example:
J2485_201212: Fastener Part Standard - Machine Screw Nuts (Metric and Inch) - SAE International
This SAE Part Standard covers selected machine screw nuts manufactured in accordance with American Society for Mechanical Engineers (ASME) dimensional standards. This document covers material most often used in ship systems and equipment but its use may be applied wherever nuts of the covered materwww.sae.org
All the above said, I have no idea where the term "imperial" came from or why anyone uses it, but it is another term some people use for some reason. "Inch" is more accurate, and saves two syllables and four letters besides, so I dunno why you'd ever use "imperial".
I looked at Amazon just out of curiosity.
- To my surprise, Tekton refers to these as "Inch" sockets. I said earlier I'd never heard them described this way - maybe I just wasn't paying attention.
- Proto includes "metric" for metric tools, but seems to just leave off any description for inch tools (e.g. "Stanley J52107 Proto 10-Piece 12 Point 3/8-Inch Drive Deep Socket Set").
- Neiko uses "SAE" in the description
- Sunex says "standard"
- Just like Proto, Williams says nothing (e.g. "Williams WSS-23RC 23-Piece 1/2-Inch Drive Shallow 12 Point Socket Set").
- Gearwrench says "SAE"
- SK and Grey used "fractional" sometimes.
Moose-LandTran
Well-known member
Imperial is simply the actual name of the system of measurement, just like metric being the name of its counterpart.
Seems odd to use the term "inch tools" when you wouldn't say "millimeter tools".
For me it's imperial and metric. SAE is a standard, as is DIN or JIS. (And Whitworth.)
I always find it funny how Americans get so aggressive and defensive about this stuff and refute the metric system when your money is metric and thou is using metric within imperial measurements.
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Mechanical Noise
Well-known member
Is imperial an informal standard or is it governed by somebody?
SAE is metric these days.
Mechanical Noise
Well-known member
It would be interesting if any tool manufacturers from an English speaking country refers to their inch tools as SAE.
Moose-LandTran
Well-known member
It's a proper governed and defined standard, just like the metric system.
Imperial units - Wikipedia
It's still a standard and not a system of measurement.
Well, to throw another term into the mix, this is what Encyclopedia Britannica says about the inch:
"inch, unit of British Imperial and United States Customary measure equal to 1/36 of a yard. "
So I guess that's where Imperial comes from. "United States Customary" is a new one for me. Apparently USCS is one abbreviation for the unit system. (https://www.engineeringtoolbox.com/uscs-d_940.html)
"USCS - United States Customary System Units - the measuring units used in the U.S. is based on the
mile
foot
inch
gallon
second
pound
USCS units are also called the Imperial units. Imperial or USCS units are gradually being replaced by SI units."
I guess USCS would be more accurate than SAE. Only problem is nobody likely knows what USCS means...
"inch, unit of British Imperial and United States Customary measure equal to 1/36 of a yard. "
So I guess that's where Imperial comes from. "United States Customary" is a new one for me. Apparently USCS is one abbreviation for the unit system. (https://www.engineeringtoolbox.com/uscs-d_940.html)
"USCS - United States Customary System Units - the measuring units used in the U.S. is based on the
mile
foot
inch
gallon
second
pound
USCS units are also called the Imperial units. Imperial or USCS units are gradually being replaced by SI units."
I guess USCS would be more accurate than SAE. Only problem is nobody likely knows what USCS means...
Moose-LandTran
Well-known member
They're usually referred to as AF or A/F which stands for "across flats". (As opposed to whitworth where a wrench size refers to the bolt's nominal thread diameter, not the hex head diameter.)
Just cause one is not used to hearing imperial doesn't mean it is not commonly used. Imperial is what the measurement system was called used in the UK, Canada, etc before they switched to metric.
Imperial describes a group of measurements as in distance, area, volume, mass, etc. just like metric or S.I. describes the same group of measurements. Some people used to/still do say "standard" instead.
In the US, aside from the names already meantioned, US measurements is what people sometimes call the group of measurements. The main difference between Imperial measurements & US measurements is volume. They share similar names for volumes but are not the same measurements.
So one could say standard, US, fractional, or imperial to describe the group but calling it SAE is not used for the group. Again it seems SAE is mostly only used by mechanics & usually only to describe tool sizes. More often people will call the group US more often than the metric group S.I.
So the name imperial may not be absolutely correct for the group of measurements but it's more appropiate than SAE, fractional, inch, DIN, JIS, ISO, etc. Call it what you will. I still call it imperial & metric to describe the groups of measurements. That's what I'm used to like others are used to calling it what they are used to.
Mechanical Noise
Well-known member
Yes, and old US wrenches commonly were sized to the bolt diameter, not the head dimension. That changed sometime around the 30s
Mechanical Noise
Well-known member
I have a bunch of BSF and CEI hardware. Should I just toss them in with the inch sized nuts and bolts and label it IMPERIAL?
Seems like there's an even more distinct difference considering thread sizes (which is relevant to this convesation) than there is with liquid measures (which is not relevant to this conversation).
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Mechanical Noise
Well-known member
It's a proper governed and defined standard, just like the metric system.
Imperial units - Wikipedia
en.m.wikipedia.org
Thanks! That clears things up. Imperial now incorporates metric standards.
US auto engineers have been working in the metric system for decades now. This makes the meaning of SAE tools unclear.
That's why none of the names in this thread to call what what matters to me except metric. It works out fine for metric. It depends on what. I'll say Imperial to call the group of measurements just as I used to say Standard & sometimes still do/have to depending on who I'm around in person. Calling the US system depending on the type of group by their appropiate terms like USCS, UTS, will confuse most people, & just don't sound right.
But if I'm labeling a tool box drawer, group of certain tools or the like, I'll never label it imperial. I may just use Inch for simplicity. But if I had BSW, BSPP, or even NPT I wouldn't group/label them as Inch.
That's why us Americans are screwed up, we don't even know what to call what or can agree on them. And I still won't convert to using metric but I do prefer using metric fasteners!
bwringer
Well-known member
I knew there were some old farts around this forum, but I think you might win the prize.
Cleaned out box this weekend and came across my whitworth sockets and wrenches I used to use on my old Norton motorcycles. Bikes gone but memories remain!