Interpreting Torque Spec? 50+10 lb/ft

[NordicDave]

Just reading a Cessna Service bulletin SB93-1 for the oil filter adapter inspection.

The reinstallation directions state to torque the mounting nut to 50+10 lb/ft. For actually torquing the nut.. what is this process according to 50+10 lb/ft?

I'm assuming it means it must be at least 50 and no more than 50 + 10 lb/ft?

 

[geezer]

I have read that as 50, do not exceed 60.

I have torqued some devices that if you went past the higher number, you replaced the item being fastened with a new one, as internal distortion had been done.

In aviation, that may be different.

 

[Bell206]

I'm assuming it means it must be at least 50 and no more than 50 + 10 lb/ft?

Yes. Usually but not always when you see a torque with only a positive spread (+10 vs +/-10) it is to allow for some sort of alignment.

 

[NordicDave]

Fantastic guys thank you!

 

[Let'sgoflying!]

I'm not sure why they presented it that way.
Why not "50-60 ft-lbs"?
Or, I believe I have seen "50 -0/+10 ft-lbs".

 

[Bell206]

I'm not sure why they presented it that way.

It's my understanding the format used to present torque values depends on what standard they used during the design of the item. As long as you're in the range life is good.

 

[Craig]

We've got a set of bolts that have a weird torque spec. They are torqued to +/- 60 lb/in window, and then have the caveat that if the locking feature does not engage, rotate the bolt up to 1/2 a flat to engage.