ASC Engineered Solutions 11/4X3/4 GALV MI REDUCER

Both openings are FPT, so it's a female-to-female bell reducer. The large end takes 1-1/4 inch male pipe thread, the small end takes 3/4 inch. Threads are cut to ASME B1.20.1 (NPT), so it mates with standard tapered pipe thread on steel or iron pipe and nipples. If you need male by female, that's a bushing, not this fitting.

It carries UL/FM approval, which is what an inspector looks for on sprinkler and fire protection lines. It's standard weight (STD) malleable iron built to ASME B16.3 for both dimensions and pressure rating, and galvanized to ASTM A-153 for wet and dry pipe systems where corrosion is a concern.

Galvanized malleable iron reducers like this 1-1/4 x 3/4 fitting are the traditional choice for galvanized steel water piping, and the galvanizing meets ASTM A-153. Match it to galvanized pipe, not black iron, or you'll set up a dissimilar-metal corrosion point at the joint. The body is ASTM A-197 malleable iron.

A bell reducer is female on both ends and adds a short run of length between the two pipes, so you thread male pipe or nipples into each side. A bushing is male on the outside and female inside, and it screws directly into an existing female port to shrink it with almost no added length. Use this 1-1/4 x 3/4 FPT reducer when you're joining two threaded pipe ends; use a bushing when you're reducing a fitting outlet you already have.

Malleable iron to ASTM A-197 is the standard material for threaded pipe fittings because it tolerates wrench torque and vibration without the brittleness of grey cast iron. This reducer is standard weight (STD) with pressure ratings per ASME B16.3. For higher working pressure you'd step up to extra heavy (XH) class instead.

The ASC Engineered Solutions part number is 311087803, a 1-1/4 x 3/4 galvanized malleable iron reducer weighing 0.65 lbs each. Sizes run 1-1/4 inch on the large end and 3/4 inch on the small end, both FPT.