ASTM A320 Grade L43 is manufactured from AISI 4340 base material and is supplied in a quenched and tempered condition. It is mainly used for large-diameter bolting, predominantly between 2 ½” and 4” diameter throughout the oil and gas industry in low-temperature environments.
Lonestar can offer this material in a standard condition, or it can be provided with supplementary testing as defined in ASTM A320. This material can also be offered fully in compliance with the additional requirements of API 20E BSL 2 and 3.
Forms
| LoneStar Manufacture | ||
| Stud Bolts | ✓ | |
| Studding | ✓ | |
| Hexagon Headed Bolting | ✓ | |
| Socket Headed Bolting | ✓ | |
| Double Ended and Waisted Studs | ✓ | |
| Associated OEM Parts | ✓ |
Sizes and Threads
| LoneStar Manufacture | ||
| Metric Coarse | ✓ | |
| Metric Fine | ✓ | |
| Imperial UNC | ✓ | |
| Imperial 8UN | ✓ | |
| Imperial UNF | ✓ | |
| ACME | ✓ | |
| Metric sizes available | Up to M100 | |
| Imperial sizes available | Up to 6.00″ |
Chemical Composition
| Carbon | 0.38-0.43 | % |
| Manganese | 0.60-0.85 | % |
| Phosphorus | 0.035 | % Max |
| Sulphur | 0.040 | % Max |
| Silicon | 0.15-0.35 | % |
| Chromium | 0.70-0.90 | % |
| Nickel | 1.65-2.00 | % |
| Molybdenum | 0.50-0.30 | % |
| Copper | – | … |
| Niobium | – | … |
| Titanium | – | … |
| Vanadium | – | … |
| Aluminium | – | … |
| Nitrogen | – | … |
Mechanical Properties
| Over 2.1/2″ to 4″ | Over 4” | |
| Tensile Strength Min, Ksi (MPa) | 125 (860) | 100 |
| Yield Strength min, 0.2% offset Ksi (MPa) | 105 (725) | 85 |
| Elongation in min% | 16 | 16 |
| Reduction of Area min% | 50 | 45 |
| Hardness Max | 321 HBW | 321 HBW |
| Hardness Max | 35 HRC | 35 HRC |
Impact Properties
| Test Temperature °F (°C) | -150 (-101) | |
| Average impact toughness, min, ft-lbf (J) | 20 (27) | |
| Average impact toughness, min, ft-lbf (J) | 15 (20) |