Technical information

OM56_Rev G Page 9 of 28

1.2 A-325 Tensioning Procedure

Throughout the installation instructions set forth in this manual, there will be references to the A-325 hardware

tensioning procedure. A-325 hardware must be properly tensioned to avoid slippage between bolted surfaces

under high loads. Slippage can cause the corresponding assembly to move or slip, resulting in antenna

misalignment. Use of A-325 hardware eliminates slippage between mating surfaces under high loading

conditions as well as the need for future retightening.

NOTE: A-325 tensioning is for final connections ONLY. NEVER LOOSEN OR REUSE A-325 HARDWARE.

Points to Keep in Mind:

 “Snug tight” is defined as tightness when plies of joint are in firm contact

 Do not proceed with felt-tip marker or tightening unless connection is final and will not be loosened again

 If after tensioning procedure the bolts are loose, discard them and replace with new hardware

 Do NOT use A-325 tensioning unless specifically called for by installation instructions

Figure 1-1a: Figure 1-1b:

Bolts Shorter than 4 Diameters Bolts Longer than 4 Diameters

A-325 hardware should be tightened according to the following tensioning procedure:

Step 1. Lubricate the bolts with provided wax stick to reduce friction

Step 2. Insert the bolt and add flat washer (if required). DO NOT allow wax to get under flat washer

Step 3. Add the nut, and tighten with your fingers

Step 4. After all connections are complete, tighten the bolts until surfaces are joined and nuts are snug (for

example, as achieved by the full effort of a SINGLE person using a standard spud wrench)

NOTE: If A-325 bolts are loosened after Steps 5 and/or 6, discard & replace with NEW hardware

Step 5. Using a Felt-Tip Marker, mark the nuts and ends of the bolts with a straight line as shown above in

Figures 1-1a (Bolts shorter than 4 diameters) and 1-1b (Bolts longer than 4 diameters)

Step 6. Tighten nuts even further, using an Extra-Long-Handled Wrench, until the nuts are:

 Moved 1/3 TURN (120°) as shown in Figure 1-1a, shorter than 4 diameters (“After Tensioning”)

 1/2 TURN (180°) as shown in Figure 1-1b, longer than 4 diameters (“After Tensioning”)