|
Grade 2 Bolt
|
| ¼” - ¾” (6” length or shorter) |
= |
74,000 psi minimum |
| ¼” - ¾” (longer than 6”) |
= |
60,000 psi minimum |
| Over ¾” |
= |
60,000 psi minimum |
|
Grade 5 Bolt
|
| ¼” – 1” |
= |
120,000 psi minimum |
| 1” – 1½” |
= |
105,000 psi minimum |
| |
|
Grade 8 Bolt
|
| ¼” - 1½” |
= |
150,000 psi minimum |
| |
|
Socket Cap Screws
|
| Up to and including ½” |
= |
180,000 psi minimum |
| Over ½” |
= |
170,000 psi minimum |
|
B7 Fasteners
|
| Up to 2½” |
= |
125,000 psi minimum |
|
Tensile Strength – Metric Bolts
|
| Class 4.6 |
= |
58,000 psi minimum |
| Class 8.8 |
= |
120,350 psi minimum |
| Class 10.9 |
= |
150,800 psi minimum |
| Class 12.9 |
= |
176,900 psi minimum |
Similarities between Metric classes and Standard grades
- Class 4.6 is similar to A307-A (Grade 2 Hex Bolts)
- Class 8.8 is similar to A449 (Grade 5 Cap Screws and Hex Bolts) and A325 (Structural Bolts)
- Class 10.9 is similar to (Grade 8 Cap Screws and Hex Bolts) and A490 (Heat Treated Structural Bolts)
- Class 12.9 is similar to (Alloy Steel Socket Head Cap Screws)
Standard inch Socket Head Cap Screws are not Grade 8 fasteners.
They differ from Grade 8 fasteners in the following ways:
- Tensile Strength (Sockets are stronger)
- Hardness (Sockets are harder)
- Head markings (Sockets do not have specific head markings)
|
Tensile Strength – Non ferrous Fasteners
|
| Pure Copper |
= |
30,000 psi minimum |
| Brass |
= |
55,000 psi minimum |
| Silicon Bronze |
= |
70,000 psi minimum |
|
