When using a torque wrench with either a U-joint socket or U-joint adapter does a correction factor need to be applied to the torque setting and if so what is it. I guess it would depend on the angle of the U-joint but is there a "rule of thumb" figure for say a 45 degree tilt.

 

Torque wrenches are not designed for use with swivel sockets.

 

How can the torque be set accurately on bolts that require swivel attachments or similar simply because it is not possible to get the torque wrench on to it straight on.

 

what are you tightening that requires you to use a torque wrench?

 

Oh - pretty much every bolt and nut has a torque setting in the service namual and so I usually try to follow these when assembling the parts. Some of the nuts are in hard to reach places.

 

To answer your original question; no, there is no correction required. Torque corrections are made only if you increase the effective LENGTH of the torque wrench between the head of the wrench and the fastener being torqued. As for any inaccuracies posed when using a swivel device, I would suggest torqueing to the higher torque value in an offered range, i.e. torque value is 25-30 ft.lb, torque to 30. The amount of any error induced by the swivel would not be significant enough to cause a problem.

 

I took a moment to look into this and my conclusion is that a correction factor is required and this factor is dependent on the length of the torque wrench as well as the angle of the swivel socket. This follows from the definition of torque which says that torque is the component of force lying in the place of rotation X perpendicular length from the point of the force to the axis of rotation.

When using swivel sockets the perpendicular distance will decrease as the wrench is bent backwards towards the axis of rotation. Also as the angle increase the force in the plane of rotation will decrease. The exact values can be calculated by simply using the decreased length as well as the appropriate component of force which can be calculated using trigonometry.

I agree that to compensate a torque setting must be increased but if the angle of the socket is large a few foot pounds will be inadequete.

comments?

 

Still stand on torque wrenches are designed for use with socket only. Just adding an extension alone is going to change the results.

That being said it is only important on critical fasters ie. Head gaskets, intake gaskets, crankshaft dampers, flywheels, bearings ect. I have never encountered having a problem gaining access to critical fasteners.

Things like a bell housing or exhaust bolt that requires a long extension and a swivel must be done by “feel”. That’s where “experience” comes in.

If it is that important to you to use a torque wrench then remove what is necessary to gain clearance.