Bolt standard ASTM A320
ASTM A320 standard bolts are high tensile steel, Alloy Steel or stainless steel bolts aiming for high pressure tasks and are manufactured in 6 different grades. The manufacturing process for ASTM A320 standard of bolt include tempering and quenching, which as a result, has made them relatively resistant in very high and very low temperatures.
ASTM A320 standard bolts are frequently used in high pressure transmission pipes, pumps, flanges , ....
ASTM A320 Mechanical Properties
| Elong % min |
Yield Stress ksi |
Tensile min ksi |
Size |
Grade |
| 16 |
105 |
125 |
up to 2-1/2 in |
L7 |
| 16 |
105 |
125 |
up to 4 in |
L43 |
| 30 |
30 |
75 |
All sizes |
B8 Class 1 |
| 12 |
100 |
125 |
up to 3/4 in |
B8 Class 2 |
| 15 |
80 |
115 |
7/8-1 in |
B8 Class 2 |
| 20 |
65 |
105 |
1-1/8 - 1-1/4in |
B8 Class 2 |
| 28 |
50 |
100 |
1-3/8 - 1-1/2in |
B8 Class 2 |
| 30 |
30 |
75 |
All sizes |
B8M Class 1 |
| 15 |
95 |
110 |
up to 3/4 in |
B8M Class 2 |
| 20 |
80 |
100 |
7/8-1 in |
B8M Class 2 |
| 25 |
65 |
95 |
1-1/8 - 1-1/4in |
B8M Class 2 |
| 30 |
50 |
90 |
1-3/8 - 1-1/2in |
B8M Class 2 |
Recommended nut and washer for ASTM A320 Bolt
| Bolt Grade | Nut | Washer |
|---|
| L7 | A194 Grade 4 or 7 | F436 |
| L43 | A194 Grade 4 or 7 | F436 |
| B8 Class 1 | A194 Grade 8 | SS304 |
| B8 Class 2 | A194 Grade 8 | SS304 |
| B8M Class 1 | A194 Grade 8M | SS316 |
| B8M Class 2 | A194 Grade 8M | SS316 |
Bolt and nut
