Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service, or both.
ASTM A194 specification covers a variety of carbon, alloy, and martensitic stainless steel nuts in the size range 1/4 through 4 in. and metric M6 through M100 nominal. It also covers austenitic stainless steel nuts in the size range 1/4 in. and M6 nominal and above. These nuts are intended for high-pressure or high-temperature service, or both.
Grade 8F Nut Grades
| Grade | Tensile Class | Raw Material |
|---|---|---|
| B5 | 4-6% Chromium Ferritic Steel | |
| B6 | 13% Chromium Ferritic Steel | |
| B6X | 13% Chromium Ferritic Steel | |
| B7 | Chromium Molybdenum Alloy Steel, Quenched & Tempered | |
| B7M | Chromium Molybdenum Alloy Steel, Quenched & Tempered | |
| B16 | Chromium-molybdenum-vanadium Alloy Steel, Quenched & Tempered | |
| B8 | Class 1 | AISI 304 Stainless Steel, Carbide Solution Treated |
| B8 | Class 2 | AISI 304 Stainless Steel, Carbide Solution Treated and Strain Hardened |
| B8A | AISI 304 Stainless Steel, Carbide solution treated in the finished condition | |
| 8C | Class 1 | AISI 347 Stainless Steel, Carbide Solution Treated |
| 8C | Class 2 | AISI 347 Stainless Steel, Carbide Solution Treated and Strained Hardened |
| 8CA | AISI 347 Stainless Steel, Carbide Solution Treated in Finished Condition | |
| B8M | Class 1 | AISI 316 Stainless Steel, Carbide Solution Treated |
| B8M | Class 2 | AISI 316 Stainless Steel, Carbide Solution Treated and Strain Hardened |
| B8MA | AISI 316 Stainless Steel, Carbide Solution Treated in Finished Condition | |
| B8M2 | AISI 316 Stainless Steel, Carbide Solution Treated and Strain Hardened | |
| B8M3 | AISI 316 Stainless Steel, Carbide Solution Treated and Strain Hardened | |
| B8P | Class 1 | AISI 305 Stainless Steel, Carbide Solution Treated |
| B8P | Class 2 | AISI 305 Stainless Steel, Carbide Solution Treated and Strain Hardened |
| B8PA | AISI 305 Stainless Steel, Carbide Solution Treated in Finished Condition | |
| B8N | AISI 304N Stainless Steel, Carbide Solution Treated | |
| B8N | AISI 304N Stainless Steel, Carbide Solution Treated and Strain Hardened | |
| B8MLCuN | AISI 304N Stainless Steel, Carbide Solution Treated | |
| B8MLCuN | UNS S31254 Stainless Steel, Carbide Solution Treated and Strain Hardened | |
| B8MLCuNA | UNS S31254 Stainless Steel, Carbide Solution Treated | |
| B8T | Class 1 | AISI 321 Stainless Steel, Carbide Solution Treated |
| B8T | Class 2 | AISI 321 Stainless Steel, Carbide Solution Treated and Strain Hardened |
| B8TA | AISI 321 Stainless Steel, Carbide Solution Treated in Finished Condition | |
| B8R | Nitronic 50/UNS S20910 Stainless Steel, Carbide Solution Treated | |
| B8RA | Nitronic 50/UNS S20910 Stainless Steel, Carbide Solution Treated in Finished Condition | |
| B8S | Nitronic 60/UNS S21800 Stainless Steel, Carbide Solution Treated | |
| B8SA | Nitronic 60/UNS S21800 Stainless Steel, Carbide Solution Treated | |
| B8LN | AISI 304LN Stainless Steel, Carbide Solution Treated | |
| B8LNA | AISI 304LN Stainless Steel, Carbide Solution Treated in Finished Condition | |
| B8MLN | AISI 316LN Stainless Steel, Carbide Solution Treated | |
| B8MLNA | AISI 316LN Stainless Steel, Carbide Solution Treated in Finished Condition | |
| 8CLN | AISI 347LN Stainless Steel, Carbide Solution Treated | |
| 8CLNA | AISI 347LN Stainless Steel, Carbide Solution Treated in Finished Condition |
Grade 8F Chemical Components
|
Grade
|
Material
|
UNS
Number |
C, %
|
Mn, %
|
Ph, %
|
S, %
|
Si, %
|
Cr, %
|
Ni, %
|
Mo, %
|
Ti, %
|
Cb & Ta, %
|
N, %
|
Other Elements, %
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
1
|
Carbon
|
0.15 min
|
1.000
|
0.040
|
0.050
|
0.400
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
|
2, 2HM, & 2H
|
Carbon
|
0.40 min
|
1.000
|
0.040
|
0.050
|
0.400
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
|
2H
|
Carbon
|
0.40 min
|
1.000
|
0.040
|
0.050
|
0.400
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
|
2HM
|
Carbon
|
0.40 min
|
1.000
|
0.040
|
0.050
|
0.400
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
|
3
|
Type 501
|
0.10 min
|
1.000
|
0.040
|
0.030
|
1.000
|
4.0-6.0
|
-
|
0.40-0.65
|
-
|
-
|
-
|
-
|
|
|
4
|
carbon, molybdenum
|
0.40-0.50
|
0.70-0.90
|
0.035
|
0.040
|
0.15-0.35
|
-
|
0.20-0.30
|
-
|
-
|
-
|
-
|
||
|
6
|
Type 410
|
S41000
|
0.150
|
1.000
|
0.040
|
0.030
|
1.000
|
11.5-13.5
|
-
|
-
|
-
|
-
|
-
|
-
|
|
6F
|
Type 416
|
S416000
|
0.150
|
1.250
|
0.060
|
0.15min
|
1.000
|
12.0-14.0
|
-
|
-
|
-
|
-
|
-
|
|
|
6F
|
Type 416Se
|
S41623
|
0.150
|
1.250
|
0.060
|
0.060
|
1.000
|
12.0-14.0
|
-
|
-
|
-
|
-
|
Selenium, 0.15 min
|
|
|
7, 7M
|
Type 4140, 4142, 4145, 4140H, 4142H, 4145H
|
0.37-0.49
|
0.65-1.10
|
0.035
|
0.040
|
0.15-0.35
|
0.75-1.2
|
-
|
0.15-0.25
|
-
|
-
|
-
|
-
|
|
|
8
|
Type 304
|
S30400
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
18.0-20.0
|
8.0-11.0
|
-
|
-
|
-
|
-
|
|
|
8A
|
Type 304
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
18.0-20.0
|
8.0-11.0
|
-
|
-
|
-
|
-
|
||
|
8C
|
Type 347
|
S34700
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
17.0-19.0
|
9.0-12.0
|
-
|
10 x Carbon Content, min
|
-
|
-
|
|
|
8CA
|
Type 347
|
S34700
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
17.0-19.0
|
9.0-12.0
|
-
|
10 x Carbon Content, min
|
-
|
-
|
|
|
8CLN, 8CLNA
|
Type 347LN
|
S34751
|
0.0005-0.020
|
2.000
|
0.045
|
0.030
|
1.000
|
17.0-19.0
|
9.0-13.0
|
-
|
0.20-0.50, 15 x Carbon Content,min
|
0.06-0.10
|
-
|
|
|
8M, 8MA
|
Type 316
|
S31600
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
16.0-18.0
|
10.0-14.0
|
2.00-3.00
|
-
|
-
|
-
|
-
|
|
8T, 8TA
|
Type 321
|
S32100
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
17.0-19.0
|
9.0-12.0
|
-
|
5 x (C+N),Min – 0.70 max
|
-
|
0.100
|
-
|
|
8F, 8FA
|
Type 303
|
S30300
|
0.150
|
2.000
|
0.200
|
0.150
|
1.000
|
17.0-19.0
|
8.0-10.0
|
-
|
-
|
-
|
-
|
-
|
|
8F, 8FA
|
Type 303 Se
|
S30323
|
0.150
|
2.000
|
0.200
|
0.06
|
1.000
|
17.0-19.0
|
8.0-10.0
|
-
|
-
|
-
|
-
|
Selenium, 0.15 min
|
|
8P, 8PA
|
Type 305 with restricted carbon
|
S30500
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
17.0-19.0
|
11.0-13.0
|
-
|
-
|
-
|
-
|
-
|
|
8N, 8NA
|
Type 304N
|
S30451
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
18.0-20.0
|
8.0-11.0
|
-
|
-
|
-
|
0.10-0.16
|
-
|
|
8LN, 8LNA
|
0.030
|
2.000
|
0.045
|
0.030
|
1.000
|
18.0-20.0
|
8.0-11.0
|
-
|
-
|
-
|
0.10-0.16
|
-
|
||
|
8MN, 8MNA
|
Type 316N
|
S31651
|
0.080
|
2.000
|
0.045
|
0.030
|
1.000
|
16.0-18.0
|
10.0-13.0
|
2.0-3.0
|
-
|
-
|
0.10-0.16
|
-
|
|
8MLN, 8MLNA
|
Type 316LN
|
S31653
|
0.030
|
2.000
|
0.045
|
0.030
|
1.000
|
16.0-18.0
|
10.0-13.0
|
2.0-3.0
|
-
|
-
|
0.10-0.16
|
-
|
|
8R, 8RA
|
XM19
|
S20910
|
0.060
|
4.0-6.0
|
0.045
|
0.030
|
1.000
|
20.5-23.5
|
11.5-13.5
|
1.50-3.0
|
-
|
0.10-0.30
|
0.20-0.40
|
Vanadium,
0.10-0.30 |
|
8S, 8SA
|
S21800
|
0.100
|
7.0-9.0
|
0.060
|
0.030
|
3.5-4.5
|
16.0-18.0
|
8.0-9.0
|
-
|
-
|
-
|
0.08-0.18
|
-
|
|
|
8MLCuN, 8MLCuNA
|
S31254
|
S31254
|
0.020
|
1.000
|
0.030
|
0.010
|
0.800
|
19.5-20.5
|
17.5-18.5
|
6.0-6.5
|
-
|
-
|
0.18-0.25
|
Copper
0.50-1.00 |
|
9C, 9CA
|
N08367
|
N08367
|
0.030
|
2.000
|
0.040
|
0.030
|
1.000
|
20.0-22.0
|
23.5-25.5
|
6.0-7.0
|
-
|
-
|
0.18-0.25
|
Copper
0.75 |
|
16
|
Chromium Molybdenum Vanadium
|
0.36-0.47
|
0.45-0.70
|
0.035
|
0.040
|
0.15-0.35
|
0.80-1.15
|
0.50-0.65
|
-
|
-
|
-
|
Vanadium 0.25-0.35
AluminumB 0.015 |
Grade 8F Hardness Requirement
|
Grade & Type
|
Brinell Hardness
|
Rockwell Hardness
|
|
|---|---|---|---|
|
C Scale
|
B Scale
|
||
|
8F
|
126-300
|
32 max
|
60 min
|
Grade 8F Proof Load (Inch Series)
|
Nominal Size, inch
|
Threads per inch
|
Stress Area inch
|
Proof Load, lbf
|
|
|---|---|---|---|---|
|
All Types of Grade 8
|
||||
|
Heavy Hex
|
Hex
|
|||
|
1/4"
|
20
|
0.0316
|
5570
|
4770
|
|
5/16"
|
18
|
0.0524
|
9170
|
7860
|
|
3/8"
|
16
|
0.0774
|
13560
|
11620
|
|
7/16"
|
14
|
0.1063
|
18600
|
15940
|
|
1/2"
|
13
|
0.1419
|
24830
|
21280
|
|
9/16"
|
12
|
0.1820
|
31850
|
27300
|
|
5/8"
|
11
|
0.2260
|
39550
|
33900
|
|
3/4"
|
10
|
0.3340
|
58450
|
50100
|
|
7/8"
|
9
|
0.4620
|
80850
|
69300
|
|
1"
|
8
|
0.606
|
106000
|
90900
|
|
1 1/8"
|
8
|
0.7900
|
138200
|
118500
|
|
1 1/4"
|
8
|
1.0000
|
175000
|
150000
|
|
1 3/8"
|
8
|
1.2330
|
215800
|
185000
|
|
1 1/2"
|
8
|
1.492
|
261100
|
223800
|
Grade 8F Marking
|
Nominal Size, inch
|
Threads per inch
|
Stress Area inch
|
Proof Load, lbf
|
|
|---|---|---|---|---|
|
All Types of Grade 8
|
||||
|
Heavy Hex
|
Hex
|
|||
|
1/4"
|
20
|
0.0316
|
5570
|
4770
|
|
5/16"
|
18
|
0.0524
|
9170
|
7860
|
|
3/8"
|
16
|
0.0774
|
13560
|
11620
|
|
7/16"
|
14
|
0.1063
|
18600
|
15940
|
|
1/2"
|
13
|
0.1419
|
24830
|
21280
|
|
9/16"
|
12
|
0.1820
|
31850
|
27300
|
|
5/8"
|
11
|
0.2260
|
39550
|
33900
|
|
3/4"
|
10
|
0.3340
|
58450
|
50100
|
|
7/8"
|
9
|
0.4620
|
80850
|
69300
|
|
1"
|
8
|
0.606
|
106000
|
90900
|
|
1 1/8"
|
8
|
0.7900
|
138200
|
118500
|
|
1 1/4"
|
8
|
1.0000
|
175000
|
150000
|
|
1 3/8"
|
8
|
1.2330
|
215800
|
185000
|
|
1 1/2"
|
8
|
1.492
|
261100
|
223800
|
ASTM A194 Grade 8F Marking
| Grade Type | Hot Forged or Cold Punched Nuts | Nuts Machined from Bar Stock |
|---|---|---|
| 8C | 8C | 8CB |