foundvettelifeisgood

Is there a conversion formula? How many foot pounds is 120 inch pounds?

:smash: :smash:

Mike Ward

there's 12 inches in a foot................

so 12 inch pounds equals 1 foot lb.

Shark Racer

Using dimensional analysis, I would guess 120 in-lb = 10 ftlb

120 in-lb x (1 ft/12in) = 10 ft-lb

-Stteve

Eddie 70

Exactly.

Larry B.

One inch pound is the force applied one inch away from the center of the bolt. One foot pound is the force applied twelve inches away. So twelve inch pounds = foot pound. Don't ask about Newton meters!!

BB wowbagger

How abot that "Newton meters" then? :jester

PRNDL

So the answer is obviously simple and simply obvious. However, it is still very important to keep the units straight, use the correct units, and not get them confused. I have seen instructions for screwing down a carb that were given in lbs/ft rather than lbs/inches, and I sure hope nobody followed those directions! :eek: MJ

Larry B.

Newtom meters are a metric measurement of torque that is seen in a lot of manuals on newer cars and even a lot of new torque wrenches have a NM scale. ........That's what I know about Newton meters. :rolleyes:

RMS73

To help confuse the issue:
1 ft-lbf = 1.356 N-M

Roger

foundvettelifeisgood

Did I really just ask how many inches in a foot? :yesnod: Believe it or not, I knew there were 12. I just couldn't believe it was that simple. Did the torque wrench maker come up with this so you'd buy an inch pound and a foot pound torque wrench? Why would my Corvette assembly manual point to one bolt and tell me in foot pounds and one right under it in inch pounds, especially if they're telling me 120-180 inch pounds?

:bs

norvalwilhelm

Most ft-lb torque wrenches don't start reading below 20 foot lbs so if they call for 10 ft lbs how do you read that on a ft-lb torque wrench. So instead they call for 120 in -lbs expecting you to go to the proper torque wrench.
I keep both in my tool box.

Larry B.

Smaller items require accurate torque to avoid over torqueing so we need smaller increnments . There are even inch oz. torque wrenches. Likewise for measuring vacuum. Inches of mercury (hg") is common but for finer measurements we use inches of water. Kinda like dollars and cents or miles and feet. :sleep:

ORVette

I read in my Hanes that you multiply inch lbs. by .083 to get foot pounds. To convert the other direction, multiply by twelve.

foundvettelifeisgood

Norval and Silver--Thanks for making sense of this. My torque wrench dips down to 10 pounds, so I'm good for 120 inch pounds. I guess if I wasn't doing the front suspension, I'd have some lesser torque values and would need the the smaller wrench. No doubt that day will come.


:smash:

spokewrench

One other thing to note is that a torque wrench is most accurate half way between its range thus the accuracy drops off towards the extremes low and high, this is why a inch pound wrench is more preferable on lower torque settings.

RMS73

:iagree:
Don't bother to use the torque wrench if it is right at the bottom like you say yours is. Accuracy does not exist at this point. Hanging a 10 pound weight from a 12" wrench would probably more accurate.
Roger

Larry B.

Breakaway or snap torque wrenches are convenient .. but the old beam type is just as accurate if not more so and they do not need to be calibrated. ;)

ddecart

Exerpt from Engineering class where the professor is putting Pascals (Newtons per meter^squared) into perspective.

Professor:
A newton is roughly 1/4 pound.
What weighs a 1/4 pound?
Class (together)
A quarter pounder! :skep:
Professor:
No...well, yeah, but not that.
A medium-sized apple weighs about a 1/4 pound
Class (mumbling):
Well, so does a quarter pounder.
.
.
.
(The rest of the story went on to compare a meter squared to a tabletop. So slice up an apple, spread it around the tabletop and that immense pressure it exerts is ONE Pascal. Now you know why stuff happens in MEGA Pascals for engineering :yesnod: )

Anyhow...
Newton: 1/4 lb
Meter: 3 feet (roughly)

Newton meter: 3/4 ft/lb
Foot lb: 1.25 Nm
Not exact, but close enough :yesnod:

Larry B.

Thanks.... I see the NM in parentheses in a lot of manuals.

foundvettelifeisgood

I just found a conversion chart in my torque wrench manual.

BTW, 73.75 ft lbs = 100 NM