Stocked through a wide range of sizes, in either mechanical tube per ASTM A519 or casing product forms, these grades of low alloy steel containing chromium and molybdenum are the most widely used alloy for oil patch applications. Usually supplied in the hardened and tempered condition at 22 HRC max. They also find favor in many applications requiring higher strength levels up to 150 KSI (0.2% PS). The grade is not NACE MR0175 approved in these conditions, and should not be used in environments containing H2S without qualification testing.
The hardenability limitations of this grade (depth to which it will harden / obtain the specified mechanical properties after heat treatment) must always be taken into account when designing and selecting equipment.
