Grain Systems Tanks PNEG-1070 - Manual (Page 46)

46 PNEG-1070 15', 18', 21', 24', 27' and 30' CHT’s
9. Hardware
Identifying Bolt Grades
( See Pages 36-39 for usage.)
NOTE: Bolts should not be tightened in excess of the torque specifications.
Bolt Size
Torque (Ft. Lbs.)
Minimum Maximum
5/16"-18 15 20
3/8"-16 35 42
7/16"-14 65 72
1/2"-13 95 105
CAUTION
Under no condition shall any other bolts be substituted for those supplied
by the manufacturer.
Grade 2 Bolts
1. Grade 2 bolts are designated with a plain head and are NOT used in GSI grain bins/silos.
Grade 5 Bolts
2. 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
3. Grade 8 bolts are designated by six (6) slash marks evenly spaced out around the
head of the bolt.
Grade 8.2 Bolts
4. Grade 8.2 bolts are designated by six (6) slash marks on the head in a sunrise pattern.
All 3/8" diameter bolts are to be grade 8 or 8.2.