American standards: ASME B 16.5 / b16.47A&B / B16.48 / ... specificationitem: carbon steel slip on flangesize: 1/2' to 48'standard: ANSI B16.5, B16.47pressure: 150lb, 300lb, 400lb, 600lb,900lb ... , cap, lap joint stub end, steel pipes, socket fittings, etc. standard carbon steel flange