These ½-Inch Thick Stainless Steel Slip-On Flanges (Series SPFH) are available in Iron Pipe Size (IPS) and Outside Diameter (O.D.) tube sizes, and are manufactured in ASTM grades 304L and 316L. These slip-on flanges comply with ANSI #150 bolt pattern specifications. IPS Size O.D. Tube Size Notesa. Material ASTM available in grades 304L & 316L.b. Meets ANSI class 150 pattern.