Bolt torque specifications, Identifying bolt grades, Bolt and nut usage – Grain Systems Tanks PNEG-4042 User Manual
Page 24
4. Bolt and Nut Usage
24
PNEG-4042 40 Series 42' and 48' Diameter Bins
Bolt Torque Specifications
The specification torque table below will help the installer determine how tight a specific bolt must be.
A bolt that has been over tightened can be just as dangerous as one that has not been tightened enough.
IMPORTANT: Bolts should not be tightened in excess of the torque specifications chart listed below.
Identifying Bolt Grades
Bolts are identified by grade (or hardness), the grade can be identified by the markings on the head of the
bolt. These markings will be in the form of slash marks and patterns. Use the following as a guide to
determine the correct bolt grade.
NOTE: Refer to 2.66" commercial tank bolting requirements for complete bolt usage.
Bolt
Minimum Torque
Maximum Torque
Sealing Joints
(Joints with
Sealing Washers)
Structural Joints
(Joints without any
Sealing Washers)
Sealing Joints
(Joints with
Sealing Washers)
Structural Joints
(Joints without any
Sealing washers)
ft./lbs.
N-m
ft./lbs.
N-m
ft./lbs.
N-m
ft./lbs.
N-m
5/16"-18 JS Grade 8 with Seal
20
27
-
-
25
34
-
-
3/8"-16 JS Grade 8 with Seal
30
41
-
-
35
47
-
-
7/16"-14 JS Grade 8 with Seal
50
68
-
-
60
81
-
-
3/8"-16 YDP Grade 8 Flanged
-
-
45
61
-
-
55
75
7/16"-14 YDP Grade 8 Flanged
-
-
85
115
-
-
95
129
1/2"-13 YDP Grade 8 Flanged
-
-
125
169
-
-
140
189
Under no condition shall any other bolts be substituted for those supplied by GSI.
CAUTION
Grade 2 Bolts
Grade 2 bolts are designated with a plain head and are not used in GSI grain bins.
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. All 3/8", 7/16" and 1/2" diameter bolts are to be grade 8 or grade 8.2.
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", 7/16" and 1/2" diameter bolts are to be grade 8 or grade 8.2.