The Alloy Steel Grade f22 slip on flanges are a low Alloy Steel Grade grade which nominally contains about 2.25% Chromium in its alloy. The flanges made from this steel grade alloy is widely used in applications involving oil patch wellhead for connectors, hangers and block valves. Hardness levels of up to 22 HRC are approved in the NACE MR0175. The low Alloy Steel Grade f22 grade is ... https://www.shasanpiping.com/alloy-steel-f22-flanges-manufacturers-exporters-suppliers-stockists.html