This specification related to ASTM A320 grade L7 includes stainless and alloy steel fasteners. These fasteners are used in various applications for low temperatures to make hardened, rolled, forged bars, bolts, screws, studs, and others.
Below we have mentioned the grades that fall under A320
A320 Grade L7
| L7 |
AISI 4140/4142 Quenched and tempered |
Mechanical properties
| Grade |
Size |
Tensile ksi, min |
Yield ksi, min |
Elong %, min |
RA % min |
HBW |
Rockwell |
| L7 |
Up to 2-1/2 |
125 |
105 |
16 |
50 |
321 Max |
35 max |
Chemical properties
| Element |
L7 (AISI 4140) |
| Carbon |
0.38 - 0.48% |
| Manganese |
0.75 - 1.00% |
| Phosphorus, max |
0.035% |
| Sulfur, max |
0.040% |
| Silicon |
0.15 - 0.35% |
| Chromium |
0.80 - 1.10% |
| Nickel |
- |
| Molybdenum |
0.15 - 0.25% |
Related hardware
| Bolt Grade |
Nut |
Washers |
| L7 |
A194 Grade 4 or 7 |
F436 |
