Application
A320 is commonly used and best described as a spec for Anchor Bolts being used in cold temperatures that have high impact results in low temperatures. A common application for A320 is for Pressure Valves, flanges, Valves and fittings for low temperatures.
Chemical Properties
| Element | L7 (AISI 4140) | L43 (AISI 4340) | B8 (AISI 304) | B8M (AISI 316) |
|---|---|---|---|---|
| Carbon | 0.37 – 0.49% | 0.38 – 0.43% | 0.08% max | 0.08% max |
| Manganese | 0.65 – 1.10% | 0.75 – 1.00% | 2.00% max | 2.00% max |
| Phosphorus, max | 0.035% | 0.035% | 0.045% | 0.045% |
| Sulfur, max | 0.040% | 0.040% | 0.030% | 0.030% |
| Silicon | 0.15 – 0.35% | 0.15 – 0.35% | 1.00% max | 1.00% max |
| Chromium | 0.75 – 1.20% | 0.70 – 0.90% | 18.0 – 20.0% | 16.0 – 18.0% |
| Nickel | 1.65 – 2.00% | 8.0 – 11.0% | 10.0 – 14.0% | |
| Molybdenum | 0.15 – 0.25% | 0.20 – 0.30% | 2.00 – 3.00% |
Mechanical Properties
| Grade | Size | Tensile,
ksi, min |
Yield,
ksi, min |
Charpy Impact
20-ft-lbf @ temp |
Elong,
%, min |
RA, %, min |
|---|---|---|---|---|---|---|
| L7 | Up to 21/2 | 125 | 105 | -150° F | 16 | 50 |
| L43 | Up to 4 | 125 | 105 | -150° F | 16 | 50 |
| B8
Class 1 |
All | 75 | 30 | N/A | 30 | 50 |
| B8M
Class 1 |
All | 75 | 30 | N/A | 30 | 50 |
| B8
Class 2 |
Up to 3/4 | 125 | 100 | N/A | 12 | 35 |
| 7/8 – 1 | 115 | 80 | N/A | 15 | 35 | |
| 11/8 – 11/4 | 105 | 65 | N/A | 20 | 35 | |
| 13/8 – 11/2 | 100 | 50 | N/A | 28 | 45 | |
| B8M
Class 2 |
Up to 3/4 | 110 | 95 | N/A | 15 | 45 |
| 7/8 – 1 | 100 | 80 | N/A | 20 | 45 | |
| 11/8 – 11/4 | 95 | 65 | N/A | 25 | 45 | |
| 13/8 – 11/2 | 90 | 50 | N/A | 30 | 45 |
Recommended Nuts and Washers
A194-L7 or L4 Nuts for the L series of the spec
A194-8, 8C, 8T, 8F, 8M, 8LN, and 8MLN
Washers are to conform to F436