
5. Bolting Requirements
18
PNEG-1859
2.66" Corrugation 135' Diameter Tank with 50 PSF Snow Roof
Bolting and Hardware Requirements
Identifying Bolt Grades
NOTE:
Bolts should not be tightened in excess of the torque specifications in below
.
Hardware usage is detailed in the bolting requirement charts
, stiffener and splice hardware
and the bolting and the hardware requirements section.
Torque (ft. lbs.)
Bolt Size
Minimum
Maximum
5/16"-18
15
20
3/8"-16
35
42
7/16"-14
65
72
1/2"-13
95
105
Under no condition shall any other bolts be substituted for those supplied by GSI.
Grade 2 Bolts
Grade 2 bolts are designated with a plain head and are not used in GSI grain bins/silos.
Grade 5 Bolts
Grade 5 bolts are designated by three (3) slash marks on the head. All 5/16" diameter
bolts are to be grade 5 or higher.
Grade 8 Bolts
Grade 8 bolts are designated by six (6) slash marks evenly spaced out around the head
of the bolt.
Grade 8.2 Bolts
Grade 8.2 bolts are designated by six (6) slash marks on the head in a sunrise pattern.
All 3/8" and 7/16" diameter bolts are to be grade 8 or grade 8.2.