| 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. | 
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| Identification Grade Mark | Specification | Fastener Description | Material | Nominal Size Range (in) | Proof Load (psi) | Min Yield Strength (psi) | Min Tensile Strength (psi) | 
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|  | 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 AISI 4145
 | 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 |