ASTM, SAE AND ISO GRADE MARKINGS AND MECHANICAL PROPERTIES FOR STEEL FASTENERS
Fastener Identification Marking Chart & Notes | Back to Reference Data
| Identification Grade Mark |
Specification | Fastener Description |
Material | Nominal Size Range (in.) |
Mechanical Properties | ||
|---|---|---|---|---|---|---|---|
| Proof Load (psi) |
Yield Strength Min (psi) |
Tensile Strength Min (psi) |
|||||
 No Grade Mark |
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 Grades A&B |
Low Carbon Steel | 1/4 thru 4 | -- | -- | |||
| SAE J429
Grade 2 |
Low or Medium Carbon Steel |
1/4 thru 3/4 Over 3/4 to 1- 1/2 |
55,000 33,000 |
57,000 36,000 |
74,000 60,000 |
||
No Grade Mark |
SAE J429 Grade 4 |
Studs | Medium Carbon Cold Drawn Steel |
1/4 thru 1- 1/2 |
-- | 100,000 | 115,000 |
B5 |
ASTM A193 Grade B5 |
AISI 501 |
1/4 Thru 4 | -- | 80,000 | 100,000 | |
B6 |
ASTM A193 Grade B6 |
AISI 410 | -- | 85,000 | 110,000 | ||
B7 |
ASTM A193 Grade B7 |
AISI 4140, 4142, OR 4105 |
1/4 thru 2-
1/2 Over 2-1/2 thru 4 Over 4 thru 7 |
-- -- -- |
105,000 95,000 75,000 |
125,000 115,000 100,000 |
|
B16 |
ASTM A193 Grade B16 |
CrMoVa Alloy Steel |
105,000 95,000 85,000 |
125,000 115,000 100,000 |
|||
B8 |
ASTM A193 Grade B8 |
AISI 304 | 1/4 and larger | -- | 30,000 | 75,000 | |
B8C |
ASTM A193 Grade B8C |
AISI 347 | |||||
B8M |
ASTM A193 Grade B8M |
AISI 316 | |||||
B8T |
ASTM A193 Grade B8T |
Bolts, Screws, Studs for High- Temperature Service |
AISI 321 | 1/4 and larger | -- | 30,000 | 75,000 |
B8 |
ASTM A193 Grade B8 |
AISI 304 Strain Hardened |
1/4 thru 3/4 Over 3/4 thru 1 Over 1 thru 1-1/4 Over 1-1/4 thru 1-1/2 |
-- -- -- -- |
100,000 80,000 65,000 50,000 |
125,000 115,000 105,000 100,000 |
|
B8C |
ASTM A193 Grade B8C |
AISI 347 Strain Hardened |
|||||
B8M |
ASTM A193 Grade B8M |
AISI 316 Strain Hardened |
95,000 80,000 65,000 50,000 |
110,000 100,000 95,000 90,000 |
|||
B8T |
ASTM A193 Grade B8T |
AISI 321 Strain Hardened |
100,000 80,000 65,000 50,000 |
125,000 115,000 105,000 100,000 |
|||
L7 |
ASTM A320 Grade L7 |
Bolts, Screws, Studs for Low- Temperature Service |
AISI 4140, 4142 or 4145 |
1/4 thru 2- 1/2 | -- | 105,000 | 125,000 |
L7A |
ASTM A320 Grade L7A |
AISI 4037 | |||||
L7B |
ASTM A320 Grade L7B |
AISI 4137 | |||||
L7C |
ASTM A320 Grade LC7 |
AISI 8740 | |||||
L743 |
ASTM A320 Grade L43 |
AISI 4340 | 1/4 thru 4 | -- | 105,000 | 125,000 | |
B8 |
ASTM A320 Grade B8 |
Bolts, Screws, Studs for Low- Temperature Service |
AISI 304 | 1/4 and larger | -- | 30,000 | 75,000 |
B8C |
ASTM A320 Grade B8C |
AISI 347 | |||||
B8T |
ASTM A320 Grade B8T |
AISI 321 | |||||
B8F |
ASTM A320 Grade B8F |
AISI 303 or 303Se |
|||||
B8M |
ASTM A320 Grade B8M |
AISI 316 | |||||
B8 |
ASTM A320 Grade B8 |
AISI 304 | 1/4 thru 3/4 Over 3/4 thru 1 Over 1 thru 1-1/4 Over 1-1/4 thru 1-1/2 |
-- -- -- -- |
100,000 80,000 65,000 50,000 |
100,000 80,000 65,000 50,000 |
|
B8C |
ASTM A320 Grade B8C |
AISI 347 | |||||
B8F |
ASTM A320 Grade B8F |
AISI 303 or 303Se |
|||||
B8M |
ASTM A320 Grade B8M |
AISI 316 | |||||
B8T |
ASTM A320 Grade B8T |
AISI 321 | |||||
 |
SAE J429 Grade 5 |
Bolts, Screws, Studs |
Medium Carbon Steel, Quenched and Tempered |
1/4 thru 1 Over 1 to 1-1/2 |
85,000 74,000 |
92,000 81,000 |
120,000 105,000 |
| ASTM A449 | 1/4 thru 1 Over 1 to 1-1/2 Over 1-1/2 thru 3 |
85,000 74,000 55,000 |
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 |
No. 6 thru 3/8 | 85,000 | -- | 120,000 |
 |
SAE J429 Grade 5.2 |
Bolts, Screws, Studs |
Low Carbon Martensitic Steel, Quenched and Tempered |
1/4 thru 1 | 85,000 | 92,000 | 120,000 |
A325 |
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 |
A325 |
ASTM A325 Type 2 |
Low Carbon Martensitic Steel, Quenched and Tempered |
1/2 thru 1 | 85,000 | 92,000 | 120,000 | |
A325 |
ASTM A325 Type 3 |
Atmospheric Corrosion Resisting 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 |
|
 BB |
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 |
 BC |
ASTM A354 Grade BC |
105,000 95,000 |
109,000 99,000 |
125,000 115,000 |
|||
 |
SAE J429 Grade 7 |
Bolts, Screws |
Medium Carbon Alloy Steel, Quenched and Tempered 4 |
1/4 thru 1-1/2 | 105,000 | 115,000 | 133,000 |
 |
SAE J429 Grade 8 |
Bolts, Screws, Studs |
Medium Carbon Alloy Steel, Quenched and Tempered |
1/4 thru 1-1/2 | 120,000 | 130,000 | 150,000 |
| ASTM A354 Grade BD |
Alloy Steel, Quenched and Tempered 4 |
||||||
No Grade Mark |
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 |
A490 |
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 |
No Grade Mark |
ISO R898 Class 4.6 |
Bolts, Screws, Studs |
Medium Carbon Steel, Quenched and Tempered |
All Sizes thru 1-1/2 |
33,000 | 36,000 | 60,000 |
No Grade Mark |
ISO R898 Class 5.8 |
55,000 | 57,000 | 74,000 | |||
8.8 or 88 |
ISO R898 Class 8.8 |
Alloy Steel, Quenched and Tempered |
85,000 | 92,000 | 120,000 | ||
10.9 or 109 |
ISO R898 Class 10.9 |
120,000 | 130,000 | 150,000 | |||