Hardware Identification
Here is a PDF from the FAA
that has some great info about hardware identification
An
article about AN Hardware by
Ron Alexander of
Alexander SportAir Workshops
Here's a PDF with a Tap and
Drill chart
AC 43.13-1B ACCEPTABLE
METHODS, TECHNIQUES,
AND PRACTICES - AIRCRAFT INSPECTION AND REPAIR
or
http://www.moneypit.net/~pratt/ac43/
Torque Spec for AN Bolts
This Chart is from Chapter 5 of the building manual from Van's.
** PLEASE NOTE: These torque specs are
the torque that you use AFTER overcoming the friction torque (call it
"Torque Drag" or there are other names) of the bolt going thru the
fastener. (i.e. if it takes 4 in/lbs of torque just to turn the AN3
bolt thru a nyloc nut, then add 4 in/lbs to the final torque requred,
which will now be 24-29in/lbs)
*** NOTE: DO NOT tap nutplates to
reduce torque required to turn screws. (At least on all structural
fastening) They are designed to lock screws.
Fine tread series, standard type nuts ( MS20365, AN310, AN315)
AN Bolt Size |
Bolt Size -
Threads per inch |
Torque Required
Inch/lbs |
Torque Requred
Foot/lbs |
AN3 |
10-32 |
20-25 inch/lbs |
1.6 - 2.0 ft/lbs |
AN4 |
1/4 - 28 |
50-70 inch/lbs |
4.2 - 5.8 ft/lbs |
AN5 |
5/16 - 24 |
100-140 inch/lbs |
8.3 - 11.6 ft/lbs |
AN6 |
3/8 - 24 |
160-190 inch/lbs |
13.3 -15.8 ft/lbs |
AN7 |
7/16 - 20 |
450-500 inch/lbs |
37.5 - 41.7 ft/lbs |
AN8 |
1/2 - 20 |
480-690 inch/lbs |
40.0 - 57.5 ft/lbs |
AN9 |
9/16 - 18 |
800-1000 inch/lbs |
66.6 - 83.3 ft/lbs |
AN10 |
5/8 - 18 |
1100-1500 inch/lbs |
91.6 - 125.0 ft/lbs |