Bolt Identification Marking
- A bolt is threaded on one end only.
- A bolt stud is threaded on both ends or the full length.
- A stud is threaded on both ends. One end is over sized to fit a tapping hole tight. The other end is threaded for a nut.
| Identification Grade Mark | Specification | Fastener Description | Material | Nominal Size Range (in) | Proof Load (psi) | Min Yield Strength (psi) | Min Tensile Strength (psi) |
|---|---|---|---|---|---|---|---|
 |
SAE J429 Grade 1 | Bolts, Screws, Studs | Low or Medium Carbon Steel | 1/4 thru 1 1/2 | 33,000 | 36,000 | 60,000 |
|
ASTM A307 Grade A & B | Bolts, Screws, Studs | Low Carbon Steel | 1/4 thru 4 | - | - | 60,000 |
|
SAE J429 Grade 2 | Bolts, Screws, Studs | Low or Medium Carbon Steel | 1/2 thru 3/4
Over 3/4 thru 1 1/2 |
55,000
33,000 |
57,000
36,000 |
74,000
60,000 |
|
SAE J429 Grade 4 | Studs | Medium Carbon Cold Drawn Steel | 1/4 thru 1 1/2 | - | 100,000 | 115,000 |
 |
ASTM A193 Grade B5 | Bolts, Screws, Studs for High Temperature Service | AISI 501 | 1/4 thru 4 | - | 80,000 | 100,000 |
 |
ASTM A193 Grade B6 | Bolts, Screws, Studs for High Temperature Service | AISI 410 | 1/4 thru 4 | - | 85,000 | 110,000 |
 |
ASTM A193 Grade B7 | Bolts, Screws, Studs for High Temperature Service | AISI 4140
AISI 4142
|
1/4 thru 2 1/2
Over 2 1/2 thru 4 Over 4 thru 7 |
-
- - |
105,000
95,000 75,000 |
125,000
150.000 100,000 |
 |
ASTM A193 Grade B16 | Bolts, Screws, Studs for High Temperature Service | CrMoVa
Alloy Steel |
1/4 thru 2 1/2
Over 2 1/2 thru 4 Over 4 thru 7 |
-
- - |
105,000
95,000 85,000 |
125,000
150.000 100,000 |
 |
ASTM A193 Grade B8 | Bolts, Screws, Studs for High Temperature Service | AISI 304 | 1/4 and larger | - | 30,000 | 75,000 |
 |
ASTM A193 Grade B8C | Bolts, Screws, Studs for High Temperature Service | AISI 347 | 1/4 and larger | - | 30,000 | 75,000 |
 |
ASTM A193 Grade B8M | Bolts, Screws, Studs for High Temperature Service | AISI 316 | 1/4 and larger | - | 30,000 | 75,000 |
 |
ASTM A193 Grade B8T | Bolts, Screws, Studs for High Temperature Service | AISI 321 | 1/4 and larger | - | 30,000 | 75,000 |
 |
ASTM A193 Grade B8 | Bolts, Screws, Studs for High Temperature Service | AISI 304
Strain Handened |
1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
100,000
80,000 65,000 50,000 |
125,000
150,000 105,000 100,000 |
 |
ASTM A193 Grade B8C | Bolts, Screws, Studs for High Temperature Service | AISI 347
Strain Handened |
1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
100,000
80,000 65,000 50,000 |
125,000
150,000 105,000 100,000 |
 |
ASTM A193 Grade B8M | Bolts, Screws, Studs for High Temperature Service | AISI 316
Strain Handened |
1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
95,000
80,000 65,000 50,000 |
110,000
100,000 95,000 90,000 |
 |
ASTM A193 Grade B8T | Bolts, Screws, Studs for High Temperature Service | AISI 347
Strain Handened |
1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
100,000
80,000 65,000 50,000 |
125,000
115,000 105,000 100,000 |
 |
ASTM A320 Grade L7 | Bolts, Screws, Studs for Low Temperature Service | AISI 4140 AISI 4142 AISI 4145 | 1/4 thru 2 1/2 | - | 105,000 | 125,000 |
 |
ASTM A320 Grade L7A | Bolts, Screws, Studs for Low Temperature Service | AISI 4037 | 1/4 thru 2 1/2 | - | 105,000 | 125,000 |
 |
ASTM A320 Grade L7B | Bolts, Screws, Studs for Low Temperature Service | AISI 4137 | 1/4 thru 2 1/2 | - | 105,000 | 125,000 |
 |
ASTM A320 Grade L7C | Bolts, Screws, Studs for Low Temperature Service | AISI 8740 | 1/4 thru 2 1/2 | - | 105,000 | 125,000 |
 |
ASTM A320 Grade L43 | Bolts, Screws, Studs for Low Temperature Service | AISI 4340 | 1/4 thru 4 | - | 105,000 | 125,000 |
|
ASTM A320 Grade B8 | Bolts, Screws, Studs for Low Temperature Service | AISI 304 | 1/4 and larger | - | 30,000 | 75,000 |
|
ASTM A320 Grade B8C | Bolts, Screws, Studs for Low Temperature Service | AISI 347 | 1/4 and larger | - | 30,000 | 75,000 |
|
ASTM A320 Grade B8T | Bolts, Screws, Studs for Low Temperature Service | AISI 321 | 1/4 and larger | - | 30,000 | 75,000 |
 |
ASTM A320 Grade B8F | Bolts, Screws, Studs for Low Temperature Service | AISI 303 or AISI 303Se | 1/4 and larger | - | 30,000 | 75,000 |
|
ASTM A320 Grade B8M | Bolts, Screws, Studs for Low Temperature Service | AISI 316 | 1/4 and larger | - | 30,000 | 75,000 |
|
ASTM A320 Grade B8 | Bolts, Screws, Studs for Low Temperature Service | AISI 304 | 1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
100,000
80,000 65,000 50,000 |
100,000
80,000 65,000 50,000 |
|
ASTM A320 Grade B8C | Bolts, Screws, Studs for Low Temperature Service | AISI 347 | 1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
100,000
80,000 65,000 50,000 |
100,000
80,000 65,000 50,000 |
|
ASTM A320 Grade B8T | Bolts, Screws, Studs for Low Temperature Service | AISI 316 | 1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
100,000
80,000 65,000 50,000 |
100,000
80,000 65,000 50,000 |
 |
ASTM A320 Grade B8F | Bolts, Screws, Studs for Low Temperature Service | AISI 321 | 1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
100,000
80,000 65,000 50,000 |
100,000
80,000 65,000 50,000 |
|
ASTM A320 Grade B8M | Bolts, Screws, Studs for Low Temperature Service | AISI 303 or AISI 303Se | 1/4 thru 3/4
Over 3/4 thru 1 Over 1 thru 1 1/4 Over 1 1/4thru 1 1/2 |
-
- - - |
100,000
80,000 65,000 50,000 |
100,000
80,000 65,000 50,000 |
 |
SAE J429 Grade 5 | Bolts, Screws, Studs | Medium Carbon Steel, Quenched and Tempered | 1/4 thru 1
Over 1 thru 1 1/2 |
85,000
74,000 |
92,000
81,000 |
120,000
105,000 |
|
ASTM A449 | Bolts, Screws, Studs | Medium Carbon Steel, Quenched and Tempered | 1/4 thru 1
Over 1 thru 1 1/2Over 1 1/2 thru 3 |
85,000
74,000 55,00 |
92,000
81,000 58,000 |
120,000
105,000 90,000 |
 |
SAE J429 Grade 5.1 | Sems | Low or Medium Carbon Steel, Quenched and Tempered | #6 thru 3/82 | 85,000 | - | 120,000 |
 |
SAE J429 Grade 5.2 | Sems | Low Carbon Martensitic Steel, Quenched and Tempered | 1/4 thru 1 | 92,000 | - | 120,000 |
 |
ASTM A325 Type 1 | High Strength Structural Bolts | Medium Carbon Steel, Quenched and Tempered | 1/2 thru 1
1 1/8 thru 1 1/2 |
85,000
74,000 |
92,000
81,000 |
120,000
105,000 |
 |
ASTM A325 Type 2 | High Strength Structural Bolts | Low Carbon Martensitic Steel, Quenched and Tempered | 1/2 thru 1 | 85,000 | 92,000 | 120,000 |
 |
ASTM A325 Type 2 | High Strength Structural Bolts | Atmospheric Corrosion Resistant Steel, Quenched and Tempered | 1/2 thru 1
1 1/8 thru 1 1/2 |
85,000
74,000 |
92,000
81,000 |
120,000
105,000 |
 |
ASTM A354 Grade BB | Bolts, Studs | Alloy Steel, Quenched and Tempered | 1/4 thru 2 1/2
2 3/4 thru 4 |
80,000
75,000 |
83,000
78,000 |
105,000
100,000 |
 |
ASTM A354 Grade BC | Bolts, Studs | Alloy Steel, Quenched and Tempered | 1/4 thru 2 1/2
2 3/4 thru 4 |
105,000
95,000 |
109,000
99,000 |
125,000
115,000 |
 |
SAE J429 Grade 7 | Bolts and Screws | Medium Carbon Alloy Steel, Quenched and Tempered | 1/4 thru 1 1/2 | 105,000 | 115,000 | 133,000 |
 |
SAE J429 Grade 8 | Bolts, Screws, Studs | Alloy Steel, Quenched and Tempered | 1/4 thru 1 1/2 | 120,000 | 130,000 | 150,000 |
|
ASTM A354 Grade BD | Bolts, Screws, Studs | Alloy Steel, Quenched and Tempered | 1/4 thru 1 1/2 | 120,000 | 130,000 | 150,000 |
|
SAE J429 Grade 8.1 | Studs | Medium Carbon Alloy or SAE 1041 Modified Elevated Temperature Drawn Steel | 1/4 thru 1 1/2 | 120,000 | 130,000 | 150,000 |
 |
ASTM A490 | High Strength Structural Bolts | Alloy Steel, Quenched and Tempered | 1/2 thru 1 1/2 | 120,000 | 130,000 | 150,000 min
170,000 max |
|
ISO R898 Class 4.6 | Bolts, Screws, Studs | Low or Medium Carbon Steel, Quenched and Tempered | All Sizes thru 1 1/2 | 33,000 | 36,000 | 60,000 |
|
ISO R898 Class 5.8 | Bolts, Screws, Studs | Low or Medium Carbon Steel, Quenched and Tempered | All Sizes thru 1 1/2 | 55,000 | 57,000 | 74,000 |
  |
ISO R898 Class 8.8 | Bolts, Screws, Studs | Medium Carbon Steel, Quenched and Tempered | All Sizes thru 1 1/2 | 85,000 | 92,000 | 120,000 |
  |
ISO R898 Class 10.9 | Bolts, Screws, Studs | Medium Carbon Steel, Quenched and Tempered | All Sizes thru 1 1/2 | 120,000 | 130,000 | 150,000 |
Tags: Fastener