**Convert kgf/mm2 to ksi or psi???
Alan Gamble
anyone out there give a conversion factor?
I'm working on a Japanese spec for 17-4PH stainless Condition
H1075 where my client wants a yield strength of 100 kgf/mm2 of
100 and I can't seem to find anything in the ASM handbooks or
anywhere else.
**Help !!!!!!!!
Alan Gamble
AlloyTech
603.890.6500 - phone
603.890.6222 - fax
--
We have a materials property and supplier database on a
fax-on-demand link. Feel free to call 800.370.6915 for a free
sample report and information.
Rich Jeniski
<74443...@CompuServe.COM> wrote:
Divide kgf/mm2 by 7.03x10exp-4 to get psi
--
Rich J
dra...@ellce.epfl.ch
<74443...@CompuServe.COM> wrote:
>I'm trying to convert values listed in kgf/mm2 to ksi or psi. Can
>anyone out there give a conversion factor?
>
>I'm working on a Japanese spec for 17-4PH stainless Condition
>H1075 where my client wants a yield strength of 100 kgf/mm2 of
>100 and I can't seem to find anything in the ASM handbooks or
>anywhere else.
>
>**Help !!!!!!!!
>
>Alan Gamble
>AlloyTech
>603.890.6500 - phone
>603.890.6222 - fax
>
pound/square inch (psi)=(kgf/square cm * 14.223)
or
kgf/square cm = pound/square inch * 0.0703
according to the formulas that I have, but it should not be hard to check it.
Greetings,
Dragan Damjanovic
Tim Dierauf
system is that one uses Newtons "N" for force. Doing this makes
conversions easy in that one does not to worry about the silly constant
"gc". It is depressing to see the troublesome "lbf" and "lbm" units from
the English system infect the SI system.
Tim
Berkeley, CA
PS. All my professional work is done in the English system. I long for
the SI system that I used in College.
S.E. Homer
> Why in the heck is any body using units of "kgf". The beauty in the SI
> system is that one uses Newtons "N" for force. Doing this makes
> conversions easy in that one does not to worry about the silly constant
> "gc". It is depressing to see the troublesome "lbf" and "lbm" units from
> the English system infect the SI system.
>
The problem is not the english system. It is confusion between force
and mass. For example, on a can of food the weight in english is given
in lb or oz but the SI equivalent is given in g or kg. The fact is that
for most people mass and weight are the same thing. If the difference
between mass and weight is important to you, then you end up with
distinctions like lbf and lbm. I remember getting points taken off an
ME assignment for expressing the answer in slugs rather than lbm. At
the time I thought that the instructor was being a jerk. Looking back
on it, he was just giving me a peek at the real world.
> Tim
> Berkeley, CA
>
> PS. All my professional work is done in the English system. I long for
> the SI system that I used in College.
--
S.E. Homer
Jim Glass ; JF ; GLASS ; x586-0375 ; (W) ; 634-000
|> I'm trying to convert values listed in kgf/mm2 to ksi or psi. Can
|> anyone out there give a conversion factor?
|>
|> I'm working on a Japanese spec for 17-4PH stainless Condition
|> H1075 where my client wants a yield strength of 100 kgf/mm2 of
|> 100 and I can't seem to find anything in the ASM handbooks or
|> anywhere else.
|>
|> **Help !!!!!!!!
|>
|> Alan Gamble
|> AlloyTech
|> 603.890.6500 - phone
|> 603.890.6222 - fax
|>
|> We have a materials property and supplier database on a
|> fax-on-demand link. Feel free to call 800.370.6915 for a free
|> sample report and information.
Sure: One Kgf is 2.2046 lbf. So a kgf/mm2 is (roughly) 1422.33343 lbf/in2.
A "kgf/cm2" is 14.22 psia; this is not a "atm", "bar" or any other standard unit.
I *HATE* it when people use mass units as units of force. Of course, the
proper units OUGHT to be N/mm2 or N/cm2 or some such.
The Russians *LOVE* this nonsense.
Jim Glass
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ghav...@fn1.freenet.edmonton.ab.ca
: Tim Dierauf <tdie...@ccnet.com> wrote:
: > Why in the heck is any body using units of "kgf". The beauty in the SI
: > system is that one uses Newtons "N" for force. Doing this makes
: > conversions easy in that one does not to worry about the silly constant
: > "gc". It is depressing to see the troublesome "lbf" and "lbm" units from
: > the English system infect the SI system.
: >
: The problem is not the english system. It is confusion between force
: and mass. For example, on a can of food the weight in english is given
: in lb or oz but the SI equivalent is given in g or kg. The fact is that
: for most people mass and weight are the same thing. If the difference
: between mass and weight is important to you, then you end up with
: distinctions like lbf and lbm. I remember getting points taken off an
: ME assignment for expressing the answer in slugs rather than lbm. At
: the time I thought that the instructor was being a jerk. Looking back
: on it, he was just giving me a peek at the real world.
If someone is doing calculation involving force and mass, they should
know the difference between mass and weight. There is no such thing
as kilograms-force! If the people working in the English system of
units want to use these phantom units, let them. As far as force
per unit area is concerned, the SI unit is the Pascal, with most
structural applications being in MPa.
--
Gordon Haverland email: ghav...@freenet.edmonton.ab.ca
101 9504 182 St. NW
Edmonton, AB T5T 3A7
403/481-8019
S.E. Homer
Agreed...for those doing the calculations. But the client "wants a
yield strength of 100 kgf/mm2". So do you go to the client and get into
an argument over units or do you put it in terms that they are
comfortable with?
BTW, here's what Webster's (a layman's reference) says about kilograms:
kilogram n. 1. The fundamental unit of mass in the metric system, equal
to approx. 2.2046 pounds. 2. A force equal to a kilogram weight, or the
product of a kilogram mass with the acceleration of gravity.
--
S.E. Homer
Jack Davidson
ghav...@fn1.freenet.edmonton.ab.ca says...
>Gordon Haverland email:
ghav...@freenet.edmonton.ab.ca
>101 9504 182 St. NW
>Edmonton, AB T5T 3A7
>403/481-8019
The use of kilograms force is not logical in the SI system. But,
for many, many years European engineers have used (as a
convenience) kilograms as the load on structures, hence the (traditional)
use of kiograms force. The strength tables they use, and the results of
strength of materials tests, have been tabulated as kilograms per square
centimeter. We hope, in these more enlightened times, that the situation
will change. But there is still some need to convert those old tables.
And I'm not so sure that their old practice is not continuing.
ja...@widomaker.com
Karen Black
>A "kgf/cm2" is 14.22 psia; this is not a "atm", "bar" or any
>other standard unit.
>
>I *HATE* it when people use mass units as units of force. Of course, the
>proper units OUGHT to be N/mm2 or N/cm2 or some such.
Proliferating pressure units are one of my pet peeves as well. Here in the
fab, we have pascals, torr, bar, mm or cm of Hg, mm or inches of water,
and of course kgf/cm^2. It's enough to drive one batty.
Karen Black
--
ka...@angelo.amd.com DoD #250: SR250, GB500, HD Sprint SS250
"If I'm typecast as a genius, who cares?"
-- Jeremy Brett, on playing Sherlock Holmes
Ken Zagzebski
Davidson) writes:
>
>In article <44sl6v$b...@news.sas.ab.ca>,
>ghav...@fn1.freenet.edmonton.ab.ca says...
>>
>>S.E. Homer (ho...@owens.ridgecrest.ca.us) wrote:
>>: Tim Dierauf <tdie...@ccnet.com> wrote:
>>
>>: > Why in the heck is any body using units of "kgf". The beauty in
the
>SI
>>: > system is that one uses Newtons "N" for force. Doing this makes
>>>>>much cut out<<<<<<<
> The use of kilograms force is not logical in the SI system. But,
>for many, many years European engineers have used (as a
>convenience) kilograms as the load on structures, hence the
(traditional)
>use of kiograms force. The strength tables they use, and the results
of
>strength of materials tests, have been tabulated as kilograms per
square
>centimeter. We hope, in these more enlightened times, that the
situation
>will change. But there is still some need to convert those old tables.
>And I'm not so sure that their old practice is not continuing.
> ja...@widomaker.com
>
I don't know why it is, but I can deal all day with force units, units
of (force-time^2)/length for mass, mass units, even mass (kg) when I
know force (kN) is proper. But my mind seems to turn to jelly when
someone throws mass units with a force subscript or force units with a
mass subscript at me. Just what _did_ they do with G and its units?!!!
Other disciplines sure have their problems too. Try asking an EE what
the MCM of a 4/0 wire is.
Ken Z.
Kevin O'Connell
[snip]
>If someone is doing calculation involving force and mass, they should
>know the difference between mass and weight. There is no such thing
>as kilograms-force! If the people working in the English system of
>units want to use these phantom units, let them.
They aren't phantom units. They aren't even dependent upon the
"English" system. The unit of "mass-force" is merely a unit which
expresses force in terms of the mass at standard gravitational acceleration
required to generate that force. This is not much different than defining a
mass unit as the mass of some volume of some standard liquid. I use a piece
of software which virtually requires that you input mass in "pure" mass units.
I know what they are and can convert to them whenever required. But it
requires me to be constantly converting all of the weight terms to mass.
I have to buy the items by weight, they are marked in weight, and all
other disciplines use the weight term. It reduces errors if I could use
the weight term in the software. It cuts down on conversion errors. But
unfortunately it was written by some pedantic person like yourself and so I
am force to constantly convert. Kgf, or lbm, etc is very clear. Everyone
knows what you are refering to. It communicates information. What is wrong
with that? Besides if you want to work with "g's" you have to express your
mass in weight terms to balance the units (or throw in the gravitational
constant which sort of defeats the purpose of working in g's).
>As far as force
>per unit area is concerned, the SI unit is the Pascal, with most
>structural applications being in MPa.
This is the one I don't understand. Psi is force per unit area.
Pressure is force per unit area. Why create a new unit? I can
understand N/m2, kgf/m2, psi, and even ksi. What was the inspiration to
create a new name for pressure? In of Hg I understand because that is
what you measure, but show me the guy who made a device which was better off
creating a new unit name for pressure. Newtons almost have a purpose.
kg/m-s^2 is a little misleading. But how did Pascals help?
Kevin O'Connell
Chad Graham
: >per unit area is concerned, the SI unit is the Pascal, with most
: >structural applications being in MPa.
: This is the one I don't understand. Psi is force per unit area.
: Pressure is force per unit area. Why create a new unit? I can
: understand N/m2, kgf/m2, psi, and even ksi. What was the inspiration to
: create a new name for pressure? In of Hg I understand because that is
: what you measure, but show me the guy who made a device which was better off
: creating a new unit name for pressure. Newtons almost have a purpose.
: kg/m-s^2 is a little misleading. But how did Pascals help?
The pascal isn't a new unit; it's just a new name for the N/m^2. The
only reason for it is to make writing and speaking easier. A parallel
case is the gauss = maxwell/cm^2 or the ampere = coulomb/sec.
C. D. Graham
Tim Shipe
[stuff deleted]
: unfortunately it was written by some pedantic person like yourself and so I
: am force to constantly convert. Kgf, or lbm, etc is very clear. Everyone
^^^^^
Good pun.
TS
Wallace Venable
>ghav...@fn1.freenet.edmonton.ab.ca () wrote:
>[snip]
>>If someone is doing calculation involving force and mass, they should
>>know the difference between mass and weight. There is no such thing
>>as kilograms-force!
Yes, as a previous post said, there is. It is one of the units in
a "metric system." There have been numerous metric systems. Kg-m-s, dyne-
cm, and so on. It is not approved SI usage. There are also "pounds-mass"
and "pounds-force" in the American Customary System to confuse us. The
British used to use tonnes/sq.in. for stress.
>>As far as force
>>per unit area is concerned, the SI unit is the Pascal, with most
>>structural applications being in MPa.
> This is the one I don't understand. Psi is force per unit area.
>Pressure is force per unit area. Why create a new unit? I can
>understand N/m2, kgf/m2, psi, and even ksi.
2
1 pascal = 1 Pa = 1 N/m It's easy enough to understand.
>What was the inspiration to create a new name for pressure?
Ah, yes, that's the part that is hard to understand. Let's blame it
on the French. Blaise Pascal ete Francais, non?
>But how did Pascals help?
2
Well, on a keyboard it's easier to do 285 Pa than 285 N/m.
We've also got 1 Joule = 1 N-m and 1 Watt = 1 volt-amp.
Keith Wootten
ocon...@slr.orl.mmc.com "Kevin O'Connell" writes:
[ quoting previous poster, much snipped ]
> >As far as force
> >per unit area is concerned, the SI unit is the Pascal, with most
> >structural applications being in MPa.
>
> This is the one I don't understand. Psi is force per unit area.
> Pressure is force per unit area. Why create a new unit? I can
> understand N/m2, kgf/m2, psi, and even ksi. What was the inspiration to
> create a new name for pressure?
> Kevin O'Connell
A good reason for this (I'm sure it's not the only one), is the
ability to represent the quantity easily using standard metric
multipliers. This is particularly important when designing
computer driven displays. For example, it's quite easy to show,
say, a process pressure in engineering units as 34.5 MPa. If
this quantity changes, it may be better to display, say, 95.4 kPa.
To write an algorithm for this is easy, neat and concise. Using
N/m2 as the unit, these figures would translate to 34.5 N/m2 and
0.0954 N/m2, making the numeric formatting difficult; the metric
multiplier would be difficult to use here without some sort of
bracketing, eg 95.4 m(N/m2) .
This is one good reason for using Litres for volume instead of
some cubed length representation. If only there were some
sensible unit for area (not Ares as in Hectare - far too ugly -
how about 1m2 = 1 Wootten?)
--
Keith Wootten
Keith Wootten
ocon...@slr.orl.mmc.com "Kevin O'Connell" writes:
> Keith Wootten <Ke...@wootten.demon.co.uk> wrote:
[snip]
> > the metric
> >multiplier would be difficult to use here without some sort of
> >bracketing, eg 95.4 m(N/m2) .
> >
> How about N/mm2?
> Kevin O'Connell
'Zackly. There's a million N/m2 in one of those fellers, and yer
standard metric multipliers come in thousands.
--
Keith Wootten