HWC Couplings are made from high-strength corrosion-resistant copper alloy, tapped for use on all standard threaded sectional rods.
Why are HWC Stainless Steel threaded couplings made with Type 303 Stainless Steel? The answer is simple: machining. Alloy 303 was specially designed to exhibit improved machinability for pieces such as these while maintaining good mechanical and corrosion resistant properties for Stainless Steel. Due to the presence of the element Sulfur (Atomic Number 16 on the Periodic Table) in the HWC Type 303 Stainless Steel composition, Alloy 303 is the most readily machineable austenitic stainless steel for a piece of this size that needs to receive threaded sections.