Torque vs. Horsepower

HP = (T*RPM)/63025 if T is in in-lbs.

I am sure you can google an answer that further explains that equation.

Shaft power is torque multiplied by angular velocity. So the answer is "no".

Unless it's @ 5252 rpm, where horsepower and torque always come out the same.

(Torque x Engine speed) / 5,252 = Horsepower

Whoops! ..Forgot to say that torque in the above equation would be in ft/lb's.

They could have the same nominal value but anyway they are two different physical entities. So the answer is absolutely NO.

Torque is effective force required to turn something. (I know it is not force) Torque is Force X Arm length

Horse power is capacity to do the work in unit time.

In FPS HP= 2 p NT/75 T is torque & N is speed of rotation per second (revolutions per second)

Thus with same small HP and with same torque requirement, you can rotate something very slow. But if you want to rotate same thing at high rotational speed you need more HP.

Forgetting the fact that torque is a rotational force for a while: you can push on the back of a lorry all day long, but, you don't do any work (measured in horse power) until it moves. (Even then the only work you are doing is in overcoming friction, and that work is dissipated in heat. To add energy, other than heat, to the system you would have to push the lorry to a higher level.)

torque is how much work you could do, horsepower is how fast you could do it. in other words, torque is how much you could lift, and horsepower is how fast you could lift it........etc....

The wrench, I think you are mixing concepts. Remember that work is an scalar product and torque is an vectorial product.

This question is often asked. I suppose because engine manufacturers list both, how much hp and how much torque a particular engine produces.

Knowing the difference is really a rudimentary engineering feat.

In linear movement we have a force F in N and a velocity v in m/s. The formula for power is simply P = F * v in kW. e.g. Pushing something at 100 N force at a velocity of 10 m/s results in 1000 Nm/s. As 1 Nm is equal to 1 J or 1 Ws, we have 1000 Ws / s or 1000 W or 1 kW power.

Rotary motion is the same, however the units are a bit different.

The force in this case is a force times a distance or N * m = Nm called a torque. But still this torque is equivalent to a force in linear motion.

The second factor, the velocity is here expressed not in m/s but in radians per second (R/s) and since one rotation or Radians have no dimension the formula for power comes out the same:

Power = force time velocity = Nm * R/s = Nm/s or watts, just as in linear motion.

E.g. 100 Nm torque * 10 R/s = 1000 Nm/s = 1000 watts or 1 kW. Keeping in mind that R/s is derived from rpm this way: R/s = rpm * pi/30.

To answer your original question, the two are not the same. Torque is a rotational force and horse power is power which is work over time.

If you multiply the torque in Nm times the revolutions of a shaft (not rpm) but in Radians then you get the work performed in Nm, namely Nm * R or Nm. (R is dimensionless).

If you divided that by time you get power, meaning to use Revolutions per time such as rpm or rps (revolutions per second), R/s = rpm * pi/30. This conversion is needed to make the units come out right.

T (Nm) = kW * 9550 / rpm, or: kW = T * n /9550, (9550 = 30000/pi).

or how about, torque would be the ability to lift 550 lb an ifintestimaly small distance from a surface, and hold it there. one horsepower would be the ability to lift 550lb one foot off the surface in one second.......two horsepower would be the ability to move 1100lb one foot off the surface in one second.......etc.....etc.....

earlier in my career, I spec'ed a servo motor by using HP instead of torque.....never again.

These links might help understand power and torque.

http://www.sportrider.com/tech/146_0402_art/index.html

http://spreadsheets.google.com/ccc?key=0ApPRT4wdrOMvcEJDSDJDbHptcnBsSFVORmdya1Q3SEE&hl=en

Horsepower was defined very precisely and carefully by James Watt. There are a couple of interesting side effects of his definition. Examples: Engine or motor horsepower is identical on both sides of a gearbox (neglecting mechanical losses), so in a car, for example, rear wheel horsepower is always engine horsepower, regardless of gear ratio. Acceleration cannot be calculated from horsepower. Formulas that are usually presented to do this are either estimation methods (changes in kinetic energy) or have a conversion from power back to force [as in acceleration = power / (mass * velocity)].

Horsepower was defined very precisely and carefully by James Watt.

From Wikipedia, and lots of other sources:-

"Watt determined that a pony could lift an average 220 lbf (0.98 kN) 100 ft (30 m) per minute over a four-hour working shift. Watt then judged a horse was 50% more powerful than a pony and thus arrived at the 33,000 ft·lbf/min figure."