MATERIAL SPECIFICATIONS
For Grades 2, 5, & 8 Internally Threaded Fasteners
Mechanical Requirements
Chemical Composition Requirements
Grade
2a.
Nut Diameter
Proof Load Stress
UNC
8UN
UNF 12 UN
& Finer
Rockwell
Hardness
C
Max.
Mn
Min.
P
Max.
S
Max.
1/4" thru 1 1/2"
90,000
90,000
C32 Max.
0.47
--
0.12
0.15
2b.
up thru 1/2"
> 1/2" thru 3/4"
> 3/4" and up
69,000
64,000
55,000
69,000
64,000
55,000
C32 Max.
C32 Max.
--
--
5
1/4" thru 5/8"
>5/8" thru 1"
>1" thru 1 1/2"
120,000
105,000
90,000
109,000
94,000
75,000
C32 Max.
C32 Max.
--
0.55
--
--
--
--
0.30
--
0.05
--
0.15
--
8
1/4" thru 1"
> 1" thru 1 1/2"
> 1 1/2"
150,000
150,000
C24 - C32
C26 - C34
C26 - C36
0.55
0.30
0.04
0.05
For Internally Threaded Fasteners Per ASTM
Mechanical Requirements
Chemical Composition Requirements
Specif.
Nut
Style
Gr.
Proof
Load
PSI
Rockwell
Hardness
C
Mn
P
S
Si
Mo
A194
A194
A194
A325-76
A563
A563
A563
A563
A563
A563
Hvy
Hex
Hvy
Hex
Hvy
Hex
Hvy
Hex
Hvy
Hex
Hex UNC
Hex UNF
Hvy Hex UNC
Hvy Hex UNF
Hex UNC
Hex UNF
Hvy
Hex UNC
2
2H
4
-
C
A
A
A
A
B
B
B
150,000
175,000
175,000
144,000
144,000
90,000
80,000
100,000
90,000
120,000
105,000
109,000
94,000
133,000
116,000
B84 Min.
C24 - C38
C24 - C38
1/4 - 1 1/8 C38 Max
1 1/4 - 1 1/2 B78-C38
B78 - C38
1/4 - 1 1/2 B68 - C32
1/4 - 4
B68 - C32
1/4 - 1 B68 - C32
1 1/8 - 1 1/2 B68-C32
1/4 - 1 B68 - C32
1 1/8 - 1 1/2 B68-C32
1/4 - 1 B68 - C32
1 1/8 - 1 1/2 B68-C32
0.04
0.40
0.40
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Min
Max
Min
Min
Min
Max
Max
Max
Max
Max
0.50
0.70
0.90
0.035
0.04
0.15
0.35
0.20
0.30
0.040
0.05
0.040
0.05
0.12
0.23
0.12
0.12
0.12
0.12
0.12
0.12
0.15
0.15
0.15
0.15
0.15
0.15
0.55
0.55
0.55
0.55
0.55
0.55
