Heavy-Duty Brass Allen Head Pipe Plug | 1/4", 3/8", 1/2" NPT

Heavy-Duty Brass Internal Hex (Allen) Head Pipe Plug

Engineered for maximum reliability and a leak-free seal, this solid brass internal hex head pipe plug is a staple fitting for high-pressure, chemical, and fluid control applications. Designed with an internal Allen head socket, this plug sits flush or low-profile in your manifold, pump port, or plumbing line, preventing snags while delivering a tight, pressure-resistant fit.

Manufactured from high-grade, corrosion-resistant brass, it easily withstands exposure to water, oils, air, and mild chemicals without degrading—making it an essential component for pressure washing setups, soft wash proportioners, hydraulic manifolds, and commercial plumbing systems.

Key Features & Benefits

•  Low-Profile Internal Allen Drive: Features an internal hex socket for quick, flush installation using standard Allen wrenches—ideal for tight clearance spaces.
•  Corrosion-Resistant Solid Brass: Heavy-duty forged brass construction resists rust, corrosion, and continuous water exposure.
•  Precision NPT Threads: Machined male NPT threads ensure smooth engagement and a tight, reliable mechanical seal when paired with thread sealant or PTFE tape.
•  Versatile Chemical & Pressure Rating: Built to handle standard high-pressure water systems, soft wash chemical proportioning blocks, air lines, and fluid manifolds.

Available Sizes

Select the exact size needed for your pump manifold or plumbing setup from our drop-down menu:

•  1/4" Male NPT: Compact fitting plug for smaller gauge ports, unloader bypasses, and secondary pump ports.
•  3/8" Male NPT: Standard sizing for mid-flow manifolds, chemical injectors, and commercial spray rigs.
•  1/2" Male NPT: Heavy-flow port plug ideal for high-GPM pressure washer manifolds, supply lines, and heavy industrial plumbing.

Common Applications

•  Pressure Washing & Soft Wash: Plugging auxiliary ports on pump heads, unloader valves, flow switches, and chemical proportioning manifolds.
•  Hydraulics & Pneumatics: Blocking off unused ports on air compressors, fluid power manifolds, and hydraulic reservoirs.
•  Plumbing & Fluid Delivery: Reliable sealing for water meters, fuel lines, boiler components, and commercial pipe runs.

Specifications

•  Material: Heavy-Duty Brass
•  Drive Style: Internal Hex / Allen Head
•  Thread Type: Male NPT (National Pipe Taper)
•  Available Sizes: 1/4", 3/8", 1/2"
•  Compatibility: Water, Air, Oil, Soft Wash Chemicals (Bleach/Surfactants)

Pro Tip: Always apply a quality pipe thread sealant (liquid thread sealant or PTFE tape) to the male NPT threads during assembly to ensure a leak-proof liquid seal under pressure.