Astec Tubes is the globally recommended manufacturer, supplier, and exporter of the very good quality of wider ranges of Alloy Steel F91 flanges. Our AS F91 collar flanges are having very good quality, high tensile strength, and rugged construction, excellent resistance to general corrosion, flawless finishes, resistance to chloride SCC and sulfuric acid. Type F91 lap joint flanges are having a chromium content of about 20-14% and it can be thus used at the temperature to 1725-1850 deg F. AS plate flanges are having temperature ranges wherein resistance to the general corrosion is quite essential. Slip-on flanges are showing very good resistance to the atmospheric condition and few chemicals and water. Flat face flanges are widely used in the AS flanges family.