Sigma 818907057 Hex Head Pipe Bushing 1-1/4 X 3/4 in 150 Lb

Product Description

The SIGMA 818907057 is a FIG 3383 standard hex head pipe bushing designed to reduce pipe thread connections from a larger male thread to a smaller female thread. Constructed from malleable iron with a black oxide finish, this bushing handles the mechanical stress of threaded pipe systems while resisting corrosion in typical service environments. It carries a 150 lb pressure rating and connects via a male NPT outer thread and a female NPT inner thread, making it a reliable fitting for reducing pipe size at a threaded joint. Licensed plumbers and pipefitters install this fitting in pressurized pipe systems where a durable, code-appropriate reducer is required.

This bushing is sized at 1-1/4 x 3/4 inch nominal, with the larger MNPT end threading into a female-threaded port or fitting and the smaller FNPT end accepting the next downstream pipe or fitting. It is suited for use in residential and light commercial piping applications including water distribution, gas piping, and general mechanical systems where malleable iron fittings are specified. The hex head profile allows a wrench to seat and tighten the bushing securely without damaging adjacent components.

Key Features

• 1-1/4 inch MNPT outer thread reduces to 3/4 inch FNPT inner thread
• 150 lb pressure-rated malleable iron construction
• Black oxide finish provides baseline corrosion resistance in typical service conditions
• Hex head design allows standard wrench engagement for controlled tightening
• FIG 3383 standard profile for consistent dimensional compatibility with threaded pipe fittings

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 1-1/4 inch to 3/4 inch NPT threaded pipe systems using malleable iron fittings rated at 150 lb.

Installation Notes

Installation is performed by licensed plumbers or pipefitters following applicable IPC or IFGC requirements depending on the service fluid. Shut off system pressure and drain the line before threading or unthreading any fittings. Apply an appropriate thread sealant or PTFE tape to the MNPT threads before installation and tighten to a snug, leak-free fit using a pipe wrench on the hex head. Do not overtighten malleable iron fittings, as the material is strong but not as ductile as steel under excessive torque.

Technical Specifications

• Figure Number: FIG 3383
• Nominal Size: 1-1/4 x 3/4 inches
• End Style: MNPT x FNPT
• Pressure Rating: 150 lb
• Material: Malleable Iron
• Finish: Black Oxide

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 818907057