4NN Series NPT Male Hollow Hex Plugs (Allen Key Pipe Plugs)

4NN Series NPT Male Hollow Hex Plug (Allen Key Pipe Plug) The 4NN Series Plug is an internal hex pipe plug fitting designed to seal tapered NPT female threaded ports. Unlike traditional external hex plugs, the 4NN series utilizes an internal Allen wrench socket (S1). 

This low-profile design allows the fitting to sit flush or near-flush inside the port, saving space and providing a clean exterior finish. The tapered NPT thread creates a tight seal as it is threaded into the mating port, effectively preventing fluid or pressure leakage in hydraulic lines, manifolds, valves, and pumps. The supplied dimensional table lists multiple thread sizes from Z1/8" to Z1", along with overall length L and internal hex size S1. 

These details help buyers identify the appropriate part number for their system specifications. NBFK can discuss OEM and customized hydraulic adapter requirements according to customer drawings, samples, or confirmed technical specifications.

Features

• NPT male tapered thread connection (E end)

• Internal hexagon (Allen socket key) drive (S1)

• Low-profile, space-saving design

• Metal-to-metal tapered thread sealing mechanism

• Multiple NPT thread sizes available

• Dimensional data provided for part selection

• OEM and customized requirements can be discussed

Specifications

Applications

The 4NN Series is intended for fluid and hydraulic sealing applications where female NPT ports must be closed off cleanly and compactly.Potential application areas include:

• Hydraulic manifolds, valves, and pump blocks

• Industrial hydraulic power units and fluid lines

• Automotive fuel, cooling, and oil gauge port sealing

• General plumbing, pneumatic, and chemical piping systems

• Space-constrained applications requiring a flush-mount plug