Stainless Steel Hex / Long Coupling CF8M Class 150 Threaded Fitting

• Product Name: Threaded Hex Long Coupling
• Material: Stainless Steel 316 / Casting Grade CF8M
• Standard: ASTM A351 (Material) / ISO 4144 (Dimensions, ref.)
• Fitting Type: Long Coupling, Hexagonal, Casting
• Connection: Female x Female Threaded (NPT or BSP)
• Pressure Rating: Class 150
• Application: Pipe Repair, Spacing, Robust Connections
• Size: Available in various sizes

The Hex Long Coupling is a functionally enhanced fitting. Compared to a standard coupling, it offers increased thread engagement and more stable support for both pipe ends, resulting in a stronger, more reliable connection. The hexagonal center design provides a convenient gripping point for a wrench during installation, making it easier to apply and withstand torque, ensuring a tight connection.

CF8M/316 stainless steel provides superior corrosion protection for piping systems. Compared to standard 304 stainless steel, 316, with its added molybdenum, offers even better resistance to chlorides and various industrial chemicals. For low-pressure systems operating in more demanding environments or requiring longer service life, choosing 316 fittings means lower long-term maintenance costs and greater operational safety.

The special design of the long hexagonal pipe coupling makes it ideal for specific applications. When repairing existing pipelines or connecting two pipe sections that are physically separated due to space constraints, the long coupling provides the necessary length and strength. It is also a superior choice over standard pipe couplings when an extremely secure threaded connection is required to withstand vibration or minor mechanical stress.

Our cast pipe fittings are produced using a precision casting (silica sol) process to achieve excellent dimensional accuracy and surface finish. The process begins with a wax pattern, which is then coated with multiple layers of refractory material to form a ceramic shell. The wax is then heated to melt and flow out. Molten stainless steel is then poured into the hollow shell. After the molten steel cools and solidifies, the shell is broken open to produce a highly precise pipe blank. This is then machined, tapped, and finished.

For this product, we explain that according to ASTM A351, CF8M is the casting grade equivalent to 316 stainless steel. While the chemical compositions of the two grades differ slightly according to the standard, their mechanical properties and corrosion resistance are considered equivalent under normal operating conditions. Therefore, in industry practice, "316" and "CF8M" are often used interchangeably. Our product meets your performance expectations for this grade.