Answer: A reducer coupling is a threaded pipe fitting with internal threads of different sizes at each end. It is used to connect two externally threaded pipe nipples or pipe ends of different diameters, thereby facilitating a transition between pipe sizes.
Note: It is distinct from a “reducing hex bushing.” A reducer coupling features a “female-to-female” (FF) threaded configuration, whereas a reducing hex bushing features a “male-to-female” (MF) threaded configuration. The two are not interchangeable.

We support NPT (ASME B1.20.1), BSPT (Rc, EN10226), BSPP (G, ISO228-1).
Threads are NOT interchangeable. Please confirm thread standard and size before order.

Standard grades:
– 304 / CF8 for water, air and general low-corrosion applications
– 316 / 316L / CF8M for coastal, brine, chemical and chloride-containing media
Duplex, 321 and other special alloys are available upon custom request.

Cast version follows ISO4144 / MSS SP-114, Class 150LB (PN20).
Forged bar machined version complies with ASME B16.11, available in 3000LB / 6000LB.
Pressure rating depends on material, wall thickness and production process.

Standard stock items: lost wax investment casting.
High-pressure, high-purity or heavy-duty application: solid bar CNC machined at higher cost.

Yes, EN10204 3.1 MTC with heat number is available. EN10204 3.2 third-party certificate can be arranged at buyer’s extra cost.

Standard: pickled matte finish.

Yes. We can mark size, grade, heat number, customer logo or brand on the flats.

Male threads are protected by plastic thread caps. Packed into export cartons, then loaded on fumigated wooden pallets with waterproof stretch film to avoid scratch and thread damage.

Typically, shipments are dispatched within 7–15 days of receiving the deposit, depending on the order quantity.

Raw material inspection → CNC machining → Thread inspection → Hydrostatic testing → Visual inspection → Final dimensional verification before packaging.

We offer FOB (Free On Board) terms, with the shipment originating from a Chinese port. We will provide a commercial invoice, packing list, and bill of lading for import customs clearance.

We offer FOB (Free On Board) or CIF (Cost, Insurance, and Freight) terms, with shipments originating from a Chinese port. We will provide a commercial invoice, packing list, and bill of lading for customs clearance.

Please provide photos, videos, and inspection records. We will assess the root cause; depending on the contractual terms, solutions may include product replacement, a partial refund, or a reshipment.”