Torque wrench question.

[Bustawrench]

When using a crowsfoot flare nut adapter on a torque wrench, is there a correction factor to account for the additional length of the adapter?

If so, what is the correction proceedure?

Thanks.

 

[petty4243]

that is a very good question, I know it does affect the torque rating... would have to do with the centerline on the drive and center line of the bolt/nut... would imagine every crows foot would be somewhat different

 

[X1 Mike]

(Length from centerline of drive to center of torque wrench handle x desired torque)
______________________________________________________________________

(Length from centerline of drive to center of torque wrench handle + length of extension)


Hard to put mathmatical formulas in here but it is top line divided by bottom line or if possible use adapter 90 degrees to the torque wrench and put the calculator away.

 

[chevelle67]

Like X1 said if the crowsfoot is perpendicular to the wrench, it does not increase the length and the moment stays the same so no correction needed.

 

[Bustawrench]

(Length from centerline of drive to center of torque wrench handle x desired torque)
______________________________________________________________________

(Length from centerline of drive to center of torque wrench handle + length of extension)


Hard to put mathmatical formulas in here but it is top line divided by bottom line or if possible use adapter 90 degrees to the torque wrench and put the calculator away.

Does the unit of measurement matter? IE: inches, MM, etc?

 

[X1 Mike]

As long as you use the same unit of measure you should be ok. I always just go by inches.

 

[rsanter]

actually putting the crows foot at 90 will change it a little (pythagorean therom) so if you need to stick to a really tight spec then you have to calculate it. if you have some room in the spec then the 90 degree trick will work fine

they actually make a specific type of crowsfoot end where all the center to center distances are the same regardless of what fastener size.

a place I used to work, we had a torque tested and we had to calibrate all the torque wrenches with the end that was to be used on it

bob

 

[Charles (in GA)]

I'll repost this:

If you are having trouble figuring it out, here is an online calculator, compliments of Norbar.

http://www.norbar.com/Calculators/TorqueWrenchExtensionCalculator/tabid/70/Default.aspx

Charles

 

[Elroy]

actually putting the crows foot at 90 will change it a little (pythagorean therom) so if you need to stick to a really tight spec then you have to calculate it. if you have some room in the spec then the 90 degree trick will work fine

How refreshing to see that someone actually understands that.

Excellent post