Fastener Identification Marking
| Grade Identification Marking | Specifications | Material | Nominal Size | Proof Load Stress | Tensile Strength Min. ksi |
Hardness Rockwell | |
|---|---|---|---|---|---|---|---|
| Min. | Max. | ||||||
 |
SAE J429 Grade 1 | Low or Medium Carbon Steel |
1/4 thru 1-1/2 | 33 | 60 | B70 | B100 |
| SAE J429 Grade 2 | 1/4 thru 3/4 over 3/4 thru 1-1/2 |
55 33 |
74 60 |
B80 B70 |
B100 B100 |
||
| ASTM A307 – Grade A | 1/4 thru 4 | – | 60 | B69 | B100 | ||
 |
SAE J429 – Grade 5 | Medium Carbon Steel,Quenched and Tempered |
1/4 thru 1 over 1 thru 1-1/2 |
85 | 120 | C25 | C34 |
| ASTM A449 – Type 1 | 74 | 105 | C19 | C30 | |||
 |
ASTM A325 – Type 1 Refer to Note 4 |
Medium Carbon Steel,Quenched and Tempered |
1/2 thru 1 over 1 to 1-1/2 |
85 74 |
120 105 |
C24 C19 |
C35 C31 |
 |
ASTM A325 – Type 2 | Low Carbon Martensite Steel, Quenched and Tempered |
|||||
 |
ASTM A325 – Type 3 Refer to Note 5 |
Atmospheric Corrosion Resistant Steel,Quenched and Tempered |
1/2 thru 1 over 1 to 1-1/2 |
85 74 |
120 105 |
C24 C19 |
C35 C31 |
 |
ASTM A354 -Grade BC | Medium Carbon Alloy Steel, Quenched and Tempered |
1/4 thru 2-1/2 over 2-1/2 thru 4 |
105 95 |
125 115 |
C26 C22 |
C36 C33 |
 |
SAE J429 – Grade 8 | Medium Carbon Alloy Steel, Quenched and Tempered |
1/4 thru 1-1/2 |
120 120 |
150 150 |
C33 C33 |
C39 C39 |
| ASTM A354 – Grade BD Refer to Note 6 |
1/4 thru 2-1/2 over 2-1/2 thru 4 |
||||||
 |
SAE J429 – Grade B2 | Low Carbon Martensite Steel, Quenched and Tempered | 1/4 thru 1 | 120 | 150 | C33 | C39 |
 |
ASTM A490 – Type 1 | Medium Carbon Alloy Steel, Quenched and Tempered |
1/2 thru 1-1/2 | 120 |
150 min. 170 max. |
C33 | C38 |
 |
ASTM A490 – Type 2 | Low Carbon Martensite Steel, Quenched and Tempered | 1/2 thru 1 | 120 |
150 min. 170 max. |
C33 | C38 |
 |
ASTM A490 – Type 3 Refer to Note 5 |
Atmospheric Corrosion Resistant Steel, Quenched and Tempered |
1/2 thru 1-1/2 | 120 |
150 min. 170 max. |
C33 | C38 |
 |
ASTM A-193 – Grade B7 | 4140 Alloy Steel Quenched and Tempered | 1/2 to 3-1/2 | 105 | 125 min. | ||
Notes regarding Fastener Identification Marking
- In addition to the indicated grade marking, all grades included in this table must be marked for manufacturer identification.
- While hex heads are shown, grade markings apply equally to products with other head configurations.
- Hardness are Brindell Hardness numbers.
- A325 Type 1 bolts may also be marked with 3 radial lines 120 degrees apart in addition to the A325 marking.
- The bolt manufacturer, at his option, may add other markings to indicate the use of atmospheric corrosion resistant steel.
- A354 Grade BD products, in sizes 1-1/2” and smaller, are identified as shown and, at the manufacturer’s option, may have the letters BD added. Larger sizes are marked only BD.
- Specifications:
ASTM 325 High strength bolts for structural steel joints SAE J429 Mechanical and material requirements for externally threaded fasteners ASTM A307 Carbon steel externally threaded standard fasteners ASTM A449 Quenched and tempered steel bolts and studs ASTM A354 Quenched and tempered alloy steel bolts, studs and other externally threaded fasteners ASTM A490 Heat treated steel structural bolts, 150 ksi minimum tensile strength ASTM A193-B7 Quenched and tempered alloy steel heavy hex bolts