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Black malleable iron square head pipe plug

Anvil

Anvil 0318901527 Square Head Plug Class 150

SKU CH-AQ6N-S80HE MPN 0318901527

Malleable iron square head plug rated Class 150 for service from -20 to 350 degrees Fahrenheit

  • Product typeDrain Components
  • Main materialHAWA
  • Solid malleable iron construction resists wear
  • Class 150 rating handles standard plumbing pressure
  • Male NPT threads ensure secure pipe connections
  • Operates from -20 °F to 350 °F for broad temperature range
  • Square head design allows easy wrench installation

Anvil Malleable Iron Square Head Plug

The Anvil 0318901527 is a Class 150 square head plug made from malleable iron for use in drain and trap assemblies. It is intended for plumbers and maintenance technicians who need a reliable threaded closure in piping systems. The black finish identifies the fitting for standard service conditions. This component provides a solid plug construction with male NPT threads.

Replaces Worn Or Damaged Threaded Plugs

This plug upgrades from deteriorated or leaking square head plugs in existing Class 150 piping networks. The jump is worth it when the original fitting shows corrosion, thread damage, or cannot hold pressure within the rated temperature range. It restores a tight seal without changing the pipe size or pressure class. The fitting suits systems operating between minus 20 degrees and 350 degrees Fahrenheit.

Simple Threaded Installation With Standard Tools

Installation requires only a wrench on the square head to engage the male NPT threads into a matching female fitting. No pre-applied thread sealant is included, so the installer must apply appropriate pipe compound or tape. The most common issue is cross-threading or over-tightening, which can crack the malleable iron or strip the threads. Ensure the mating threads are clean and aligned before applying torque.

How it compares

Measured against everything we stock in Drain Stoppers, Strainers & Traps, at today’s prices. Recalculated every night.

Price $0.53
Cheaper than about 99% of the 4,240 comparable items (median $31.99).

Specifications

Product
Brand nameAnvil
Model name0318901527
Product typeDrain Components
Size & build
Main materialHAWA

Questions about this item

What thread size does the 3/8 in NPT plug need to mate with?

It requires a matching 3/8 in NPT female thread on the pipe or fitting.

How do you install the square head plug without damaging the threads?

Apply thread sealant tape or paste, then tighten the square head with a wrench until snug without over-torquing the malleable iron body.

When should this Class 150 malleable iron plug be replaced?

Replace it if the threads show corrosion, the square head rounds off, or the system exceeds the 350 °F temperature limit.

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