Product Description
The B K Mueller Industries 521-984HC is a black hex bushing designed to reduce pipe thread sizes in threaded piping systems. This fitting connects a 2-inch female thread to a 3/4-inch male thread, allowing tradespeople to transition between pipe sizes without additional adapters. The black finish indicates a malleable iron or steel construction suited for gas, air, and water distribution lines. Plumbers and pipefitters install this fitting during new construction and retrofit work where downsizing a threaded connection is required. Each package contains 5 pieces, making it practical for multi-point installations or job-site stock.
This hex bushing is used in residential and light commercial plumbing and gas piping applications. The hex head profile allows for standard wrench engagement during installation, ensuring a secure, leak-free threaded joint. Typical applications include gas distribution manifolds, compressed air systems, and black iron water supply piping where a 2-inch to 3/4-inch reduction is needed at a threaded fitting, valve, or appliance connection.
Key Features
- Reduces 2-inch female thread to 3/4-inch male thread in a single fitting
- Hex head profile provides full wrench engagement for proper torque
- Black finish suitable for gas, air, and water piping service
- Sold in a 5-piece package for multi-point or backup inventory use
- Compact bushing design eliminates the need for a separate coupling and nipple
Compatibility
Designed as an OEM-style replacement and standard fitting for threaded black iron piping systems requiring a 2-inch to 3/4-inch pipe thread reduction.
Installation Notes
A licensed plumber or pipefitter should install this fitting in accordance with applicable local codes and the International Fuel Gas Code (IFGC) or International Plumbing Code (IPC) as appropriate to the service. Shut off and depressurize the line before disassembling any existing threaded connection. Apply an approved thread sealant or PTFE tape to the male threads before assembly. Do not over-extend engagement beyond full thread makeup, as this can crack fittings or distort seating surfaces.
Technical Specifications
- Inlet Thread Size: 2 inches (female)
- Outlet Thread Size: 3/4 inches (male)
- Finish: Black
- Package Quantity: 5 pieces
- Package Weight: 5 pounds
- Unit of Measure: EA
Standard Information
- Brand: B K Mueller Industries
- Manufacturer Part Number: 521-984HC








