formula for finding torque with different length levers

[joshuaj97]

trying to figure out how to calculate torque using a hydraulic cylinder with a known amount of force on a lever approx 18" long transfering this into a 1.5 inch socket drive, trying to torque a bolt using a pressure reading from a hydraulic gauge is the main objective thanks

[GlennW]

Seems like hyd pressure in psi multiplied by the piston area of the hyd ram , applied to a 12" lever would be the torque applied in ft. lbs.

[stevec]

Multiplied by 1.5 for an 18 inch lever.

[dly31]

...Assuming the cylinder is at right angles to the lever. Otherwise multiplied by the cosine of the angle deviation (I think).

[stevec]

You're right Don, the operation of a linear thrust device (piston rod) is effective for somewhat less than 180 Deg. of the arc of the lever it is acting on. And, maximum torque is only developed at the centre of the arc i.e. 90 deg.

[fourjc]

What you need is a torque multiplier, I know this is not the answer you are looking for but it's the only accurate way... here is a cheap setup that seems to work well..
http://www.youtube.com/watch?v=B5Ctp89AH58