I have not previously asked a question on this forum. So, hopefully I am doing this correctly.
My question is about what torque value should be applied to bolts. I suspect that I may be over thinking this. But, I would like to hear what others are doing.
My questions come from reading section 5.20 NUT AND BOLT TORQUES (i.e. on page 05-13 of the manual, revision 1).
I understand that the preference is to torque the nut rather than the head of the bolt. Further, the end being turned (i.e. nut or head of the bolt) is to have a washer installed to reduce the friction and provide a wear surface.
The tables provided are to be used when torquing the nut. Further, that these values are for clean and dry threads. I find it a bit confusing that the AN365 nut (i.e. elastic stop nut) is called a Standard Nut rather than a Self Locking Nut.
Regarding torquing the head of a bolt, it states that the shank of the bolt is to be lubricated and the applied torque needs to be increased from the nut torque shown in the table by the friction torque to turn the bolt. The friction torque is to be determined by measuring the torque needed to pull the bolt head until it nearly contacts the bearing surface. To be able to measure this friction torque one would need a torque wrench capable of measuring very low torque values. These torques are lower torques than the torque wrenches sold by Avery or Cleveland and would require a very expensive torque wrench to measure.
So, how are people determining what torque should be applied to the head of bolts? What torque specification are people using for bolts going into nutplates? Does anyone else find it confusing that in the last paragraph the example in the last paragraph has results in a different value that shown in the table for MS21043-3 nuts?
Just seeking to understand.
Thanks.
Brett H
Columbus, Indiana
Working on the tail kit
Paid in October 2013
My question is about what torque value should be applied to bolts. I suspect that I may be over thinking this. But, I would like to hear what others are doing.
My questions come from reading section 5.20 NUT AND BOLT TORQUES (i.e. on page 05-13 of the manual, revision 1).
I understand that the preference is to torque the nut rather than the head of the bolt. Further, the end being turned (i.e. nut or head of the bolt) is to have a washer installed to reduce the friction and provide a wear surface.
The tables provided are to be used when torquing the nut. Further, that these values are for clean and dry threads. I find it a bit confusing that the AN365 nut (i.e. elastic stop nut) is called a Standard Nut rather than a Self Locking Nut.
Regarding torquing the head of a bolt, it states that the shank of the bolt is to be lubricated and the applied torque needs to be increased from the nut torque shown in the table by the friction torque to turn the bolt. The friction torque is to be determined by measuring the torque needed to pull the bolt head until it nearly contacts the bearing surface. To be able to measure this friction torque one would need a torque wrench capable of measuring very low torque values. These torques are lower torques than the torque wrenches sold by Avery or Cleveland and would require a very expensive torque wrench to measure.
So, how are people determining what torque should be applied to the head of bolts? What torque specification are people using for bolts going into nutplates? Does anyone else find it confusing that in the last paragraph the example in the last paragraph has results in a different value that shown in the table for MS21043-3 nuts?
Just seeking to understand.
Thanks.
Brett H
Columbus, Indiana
Working on the tail kit
Paid in October 2013