Merit Brass K419-06 Pipe Locknut 3/8 in 304 Ss 150 Psi

Product Description

The MERIT BRASS K419-06 is a 3/8 inch pipe locknut manufactured from 304 stainless steel and designed for threaded piping assemblies. Locknuts are used to secure fittings, bushings, or other threaded components against a panel, wall, or mating surface, holding them firmly in position under system pressure. This unit carries a 150 psi pressure rating and features a Female National Pipe Straight Locknut (FNPSL) end connection, making it suitable for straight-thread applications where a sealed, locked position is required. The overall length is 1-1/32 inches. Licensed plumbers and pipefitters are the typical installers for this type of hardware.

This locknut is appropriate for residential and light commercial plumbing, instrumentation, and fluid-handling systems where corrosion resistance is a priority. 304 stainless steel construction makes it a sound choice for wet environments, potable water lines, and mild chemical service. The threaded FNPSL connection conforms to ISO standards, supporting compatibility across a broad range of compliant fittings and system components. It ships as a single unit and is commonly used in maintenance, repair, and new installation work.

Key Features

• 304 stainless steel construction for corrosion resistance in wet and mild chemical environments
• 3/8 inch fitting size with FNPSL (Female National Pipe Straight Locknut) end connection
• 150 psi pressure rating suitable for low-to-medium pressure fluid systems
• Threaded connection type for straightforward installation and removal
• ISO-compliant standard for broad cross-system compatibility
• Compact profile at 1-1/32 inches in length and 0.05 pounds

Compatibility

Designed as an OEM-style replacement or service component for 3/8 inch threaded piping systems requiring an FNPSL locknut in 304 stainless steel.

Installation Notes

Installation is typically performed by a licensed plumber or pipefitter. Depressurize and drain the affected line before beginning work on any fitting or locknut. Use appropriate pipe wrenches or strap wrenches rated for stainless steel hardware to avoid galling the threads. Follow applicable IPC or local plumbing code requirements for pressure system repairs and new installations.