Class 1 and Class 2 of ASTM A350/ ASME SA-350 grade LF2 have the same chemical composition and mechanical properties. Even the allowable stresses of Class 1 and Class 2 in ASME Codes are the same. The main characteristic that distinguishes Class 1 from Class 2 is its minimum applicable temperature. The minimum applicable temperatures are -50°F [-46°C] for LF2 Class 1 and -0°F [-18°C] for LF2 Class 2, respectively. The minimum applicable temperature is also the standard Charpy V-notch impact test temperature.