Alloy Steel Large Threaded Rod , ASTM A320 L7 Forged Double End Threaded Rod
ASTM A320 L7 Full Threaded steel Rod ASTM A320 L7 Alloy Steel threaded rods
The ASTM A320 specification covers alloy steel and stainless steel bolting materials for low temperature service. This standard covers rolled, forged, or strain hardened bars, bolts, screws, studs, and stud bolts used for pressure vessels, valves, flanges, and fittings.
1. Specifications and materials
| dentification | L7, L7M, L70 | L7A, L71 | L7B, L72 | L43 |
| Grade | Chromium- Molybdenum (AISI 4140, 4142, or 4145) |
Carbon- Molybdenum (AISI 4037) |
Chromium- Molybdenum (AISI 4137) |
Nickel-Chromium- (AISI 4340) |
2. Chemical composition of A320 L7 steels.:
| 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 | 0.04% | 0.04% | 0.05% | 0.05% |
| Sulfur, max | 0.04% | 0.04% | 0.03% | 0.03% |
| 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% |
3. Mechanical properties of A320 L7,L7ML43 and so on..
| Grade and Class | Diameter | Heat Treatment | Tensile Str Min KSI |
Yield Str 0.2% Offset KSI |
Elongation in 2in. Min, % |
Reduction of Area Min, % |
Hardness max |
| FERRITIC STEELS | |||||||
| L7, L7A, L7B, L7C, L70, L71, L72, L73 |
2-1/2" and under | quench and tempered | 125 | 105 | 16 | 50 | |
| L43 | 4" and under | quench and tempered | 125 | 105 | 16 | 50 | |
| L7M | 2-1/2" and under | quench and tempered @ 1150F, min |
100 | 80 | 18 | 50 | 235 HB / 99HRB |
| L1 | 1" and under | quench and tempered | 125 | 105 | 16 | 50 | |
| AUSTENTIC STEELS | |||||||
| CLASS 1: B8, B8C, B8M, B8P, B8F, B8T, B8LN, B8MLN |
ALL | carbide solution treated | 75 | 30 | 30 | 50 | 223 HB or 96 HRB |
| CLASS 1A: B8A, B8CA, B8MA, B8PA, B8FA, B8TA, B8LNA, B8MLNA |
ALL | carbide solution treated | 75 | 30 | 30 | 50 | 192 HB or 90 HRB |
| CLASS 2: B8, B8C, B8P, B8F, B8T |
3/4" and under | carbide solution treated and strain hardened |
125 | 100 | 12 | 35 | 321 HB or 35 HRC |
| over 3/4 to 1" incl | 115 | 80 | 15 | 30 | 321 HB or 35 HRC | ||
| over 1" to 1-1/4" incl | 105 | 65 | 20 | 35 | 321 HB or 35 HRC | ||
| over 1-1/4" to 1-1/2" incl | 100 | 50 | 28 | 45 | 321 HB or 35 HRC | ||
| CLASS 2: B8M | 3/4" and under | carbide solution treated and strain hardened |
110 | 95 | 15 | 45 | 321 HB or 35 HRC |
| over 3/4 to 1" incl | 100 | 80 | 20 | 45 | 321 HB or 35 HRC | ||
| over 1" to 1-1/4" incl | 95 | 65 | 25 | 45 | 321 HB or 35 HRC | ||
| over 1-1/4" to 1-1/2" incl | 90 | 50 | 30 | 45 | 321 HB or 35 HRC |
4. Sizes we can also for full Threaded rods: 1/4‘’ to 4‘’
5. MOQ: Normally we don't have any MOQ requirements, because we produce threaded rods for big quantity every month
6. Delivery time : 7-30 days upon to the sizes & quantity.
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.