The Forged Carbon Steel Threaded Coupling (also called a pipe coupling or straight coupling) is a high pressure fitting used to join two threaded pipes together in a straight line. The fitting is forged from ASTM A105 carbon steel, providing superior strength and pressure containment compared to cast fittings. It has female NPT or BSP threads on both ends. The threads are full engagement type, meaning they are designed to accept the full length of the pipe thread for maximum holding power. The coupling is available in Class 3000 or Class 6000 pressure ratings. Hex couplings have a hexagonal outer surface for easy wrench tightening; round couplings have a smooth outer surface for use in tight spaces where wrench clearance is limited. This fitting is the standard method for joining small bore, high pressure threaded pipe systems.
Why Choose Us / Advantage
Full Thread Depth: Threads machined to full depth — no short threads.
Hex or Round: We stock both configurations — choose based on your space.
Pressure Rated: Class 3000 and 6000 options for system compatibility.
100% Pressure Tested: Sample tested from each batch.
Quick Connect: No welding — simply screw pipes into both ends.
Technical Data
★ Specification Class 3000 Class 6000
★ Material Forged Steel ASTM A105 Forged Steel ASTM A105
★ Type Straight coupling Straight coupling
★ Connection Female NPT / BSP both ends Female NPT / BSP both ends
★ Shape Hex or Round Hex or Round
★ Pressure 3000 PSI 6000 PSI
★ Size Range 1/8″ – 4″ 1/8″ – 2″
★ Standard ASME B16.11 ASME B16.11
Applications
● High pressure hydraulic piping runs
● Steam tracing lines (connecting pipe sections)
● Instrument air distribution networks
● Chemical transfer small bore lines
● Fire protection small bore branch lines
