B K/mueller Inds(import) 521-942HC Black Hex Bushing

Product Description

The B K/MUELLER INDS(IMPORT) 521-942HC is a black hex bushing designed to reduce pipe thread connections from 3/4 inch male NPT to 3/8 inch female NPT. This fitting is a standard threaded reducer used in gas piping, compressed air, and general plumbing systems where a pipe size change is needed at a threaded joint. The hex profile allows for wrench engagement during installation, providing secure make-up torque without slipping. It is sold in packages of 75 units, making it well suited for contractors and supply houses stocking fittings in volume.

This hex bushing is commonly installed in residential and light commercial applications wherever a threaded pipeline requires a step-down reduction. Typical uses include gas line distribution manifolds, air compressor outlet connections, hydraulic systems, and general-purpose black iron piping assemblies. Plumbers, pipefitters, and HVAC technicians encounter this fitting when transitioning between differing pipe sizes at valves, regulators, or equipment ports.

Key Features

• Reduces 3/4 inch male NPT to 3/8 inch female NPT in a single threaded fitting
• Hex body profile allows full wrench engagement for proper tightening
• Black iron finish suitable for gas and air service applications
• Packaged in quantities of 75 units per package for contractor use
• Compact bushing-style design minimizes added length in the piping run

Compatibility

Designed as an OEM-style replacement and standard-stock hex bushing for threaded black iron piping systems using 3/4 inch to 3/8 inch NPT connections.

Installation Notes

Installation is performed by licensed plumbers or pipefitters in accordance with applicable codes such as the IFGC or IPC. Shut off the gas or air supply and depressurize the line before disassembling any threaded fittings. Apply an approved thread sealant or PTFE tape rated for the intended service medium to the male threads before assembly. Use a properly sized wrench on the hex body to achieve a secure, leak-free joint without over-stressing the fitting.