ASTM A707 Grade L5 ASTM A707 Grade L5 Class 4 Weld Neck Raised Face (WNRF) flanges are high-end forged connecting components developed for low-temperature, high-pressure oil and gas service conditions. Manufactured from Grade L5 low-carbon nickel-chromium-molybdenum-copper-niobium alloy steel and matched with the highest strength level Class 4, these flanges deliver industry-leading pressure-bearing capacity while ensuring excellent low-temperature impact toughness, making them perfectly suited for long-term stable operation of oil and gas pipelines and high-pressure piping systems in cold regions.