A

aeropunk

Active Member
Let's assume for a moment that I'm a bumbling idiot and have no idea how to reference a simple table like the one pictured below. Let's assume that I've got a garden-variety AN bolt (let's say an AN3-4A for kicks), and I'm trying to find the proper torque value for it. Let's go a step further, and pretend that bolt is going into a nutplate rather than a nut, and thus I'll be applying the torque to the bolt rather than the nut. Can somebody give me the idiot-proof method for going from an AN-hardware value to the Nut-Bolt size column on the left-hand side of the chart? I've read all the standard refs (AC43.13, Aviation Mechanic Handbook, Standard Aircraft Handbook), and I'm still not making the connection. What am I missing? Thanks in advance!

torque-values.jpg
 
The idiot-proof method is to use the torque table in Section 5 of your plans that Van's sent you. Using your table, though, an AN3 bolt has 10-32 threads, and you'd use the standard torque like you would with an AN365 nut, so 20-25 in-lb.

-Rob
 
Torque

When tightening a bolt into a nutplate or a self locking nut onto a bolt, you first need to note the torque needed to turn the fastener against the self locking feature. Then you need to add this torque to the tightening torque from the table.
 
And unless otherwise noted, all torque values are for dry fit-up. BoeLube / oil / grease on the threads will change the torque characteristics considerably.
 
n8zg said:
And unless otherwise noted, all torque values are for dry fit-up. BoeLube / oil / grease on the threads will change the torque characteristics considerably.
Click to expand...

Unless you are working on a Lycoming engine - then you lubricate the threads and use this table -

torques.jpg
 
This is where a Dial Face Torque Wrench is real handy!

terrye said:
When tightening a bolt into a nutplate or a self locking nut onto a bolt, you first need to note the torque needed to turn the fastener against the self locking feature. Then you need to add this torque to the tightening torque from the table.
Click to expand...
 
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