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Hardware Requirements
Overview
Installation of all bolts should be in accordance to AISC Specifications for structural joints using ASTM
A325 bolts. No other bolts should be substituted for those supplied by GSI. The following is adapted from
AISC J3.
Hardware Tightening – Splice Connections
Using an impact wrench, or spud wrench, tighten all fasteners until the splices are touching. Using bar on
wrench, turn the nut the appropriate turn distance (degree) to achieve the desired pretension. It is critical
that the head of the bolt be held with a wrench so that it does not turn during tightening.
Bolt Tightening
Pretensioned Bolts
1. Pretension is required for the bolts that connect the sections of the tower columns.
2. Using a calibrated wrench or the turn-of-the-nut method, this pretension can be done using the
values in the following table.
Minimum Bolt Pretension for A325 Bolts
Bolt Diameter (in.)
Pretension (kips)
7/8
39
1
51
1-1/4
71
1-1/2
103
PNEG-2115
2-Leg and 4-Leg Towers
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