SAE J429 Grade 8 Threaded Rod
Key Points of ASTM A320 Threaded Rods:
Application: Designed for use in low-temperature environments such as LNG plants, cryogenic processing, pressure vessels, and offshore facilities.
Materials: Typically chromium-molybdenum alloy steels with heat treatment (quenched and tempered) to enhance toughness.
Grades: ASTM A320 includes various grades such as L7, L7M, B8, B8M, etc., with L7 and L7M being the most widely used for carbon/alloy steels.
Testing Requirements: Must pass impact testing (Charpy V-notch) at -50°F (-46°C) to ensure toughness and resistance to brittle fracture at low temperatures.
| 01 ASTM A320 Grade L7 Threaded Rod | Material: Chromium-molybdenum steel (similar to AISI 4140/4142), quenched and tempered. Tensile Strength: Minimum 125 ksi (862 MPa). Applications: Widely used in cryogenic service, pressure vessels, piping systems, and flanges in oil & gas and LNG industries. Temperature Range: Suitable for low-temperature service down to -50°F (-46°C). Properties: High mechanical strength combined with toughness. Specifically designed for cold-weather and cryogenic applications. Reliable for structural bolting in harsh environments. |
| 02 ASTM A320 Grade L7M Threaded Rod | Material: Similar alloy steel as L7, but with lower hardness requirements to improve ductility. Tensile Strength: Lower than L7 (typically around 105 ksi / 724 MPa minimum). Applications: Used where impact toughness is critical, such as in marine, offshore, and cryogenic equipment. Temperature Range: Suitable for low-temperature service down to -50°F (-46°C). Properties: Better ductility and toughness than L7. Reduced hardness to minimize the risk of brittle fracture. Recommended for environments with higher safety requirements or risk of stress corrosion cracking. |
| Feature | ASTM A320 Grade L7 Threaded Rod | ASTM A320 Grade L7M Threaded Rod |
| Material | Cr-Mo alloy steel, quenched & tempered | Cr-Mo alloy steel, quenched & tempered |
| Tensile Strength | ≥ 125 ksi (862 MPa) | ~105 ksi (724 MPa) minimum |
| Yield Strength | ≥ 105 ksi (724 MPa) | Lower than L7 |
| Impact Test | Required at -50°F (-46°C) | Required at -50°F (-46°C) |
| Applications | Cryogenic piping, pressure vessels, LNG plants | Offshore, marine, critical cryogenic equipment |
| Properties | Higher strength, less ductile | Slightly lower strength, improved toughness |
ASTM A320 L7, L7M
ASTM A320 L7, L7M
ASTM A320 L7, L7M
