Allied Moulded 9331-EWK 1-Gang...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$3.89
Allied Moulded 9331-EWK 1-Gang Fiberglass Reinforced Switch Box

Allied Moulded 9331-EWK 1-Gang Fiberglass Reinforced Switch Box

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Model: 9331-EWK

In Stock (leaves warehouse same day if ordered before 3pm ET)

$3.89
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Allied Moulded 9331-EWK 1-Gang Fiberglass Reinforced Switch Box

The Allied Moulded 9331-EWK is a 1-Gang residential/receptacle electrical switch box built from fiberglass reinforced thermoset polyester, part of the Allied Moulded FiberglassBox™ line. Measuring 2-3/8-Inch x 3-1/4-Inch x 2-1/2-Inch with a 14-Cubic-Inch interior capacity, this box is engineered for single-gang switch and receptacle installations where a durable, non-metallic enclosure is required. The fiberglass reinforced thermoset polyester construction resists corrosion, moisture, and impact, making it a dependable alternative to traditional metallic or standard plastic boxes in residential wiring applications.

Key Features

  • Configuration: 1-Gang design supports a single switch or receptacle device in residential wiring installations.
  • Durable Construction: Fiberglass reinforced thermoset polyester provides strength and long-term resistance to corrosion and impact compared to standard plastic boxes.
  • Dimensions: 2-3/8-Inch x 3-1/4-Inch x 2-1/2-Inch box footprint sized for standard single-gang device installations.
  • Interior Capacity: 14-Cubic-Inch volume provides adequate wiring space for a single switch or receptacle and associated conductors.
  • Residential/Receptacle Rated: Purpose-built as a residential/receptacle electrical switch box for common household wiring applications.
  • FiberglassBox™ Line: Part of the Allied Moulded FiberglassBox™ product family, engineered specifically around fiberglass reinforced thermoset polyester construction.

Technical Specifications

  • Gangs: 1-Gang
  • Material: Fiberglass Reinforced Thermoset Polyester
  • Dimensions: 2-3/8-Inch x 3-1/4-Inch x 2-1/2-Inch
  • Interior Capacity: 14-Cubic-Inch
  • Box Type: Residential/Receptacle Electrical Switch Box
  • Product Line: FiberglassBox™

Typical Applications

  • Residential Switch and Receptacle Installations
  • New Construction Wiring
  • Renovation and Remodel Electrical Work
  • Single-Gang Device Mounting
  • Applications Requiring Corrosion-Resistant Non-Metallic Boxes

Why Allied Moulded?

Allied Moulded's FiberglassBox™ line combines fiberglass reinforced thermoset polyester construction with practical, code-compliant sizing to deliver a rugged, corrosion-resistant alternative for residential switch and receptacle installations. The 9331-EWK's 14-Cubic-Inch capacity and 1-Gang configuration make it a straightforward, reliable choice for electricians and contractors seeking a durable non-metallic box for everyday residential wiring projects.

Manufacturer Resources

Spec Sheet

Product Specs

list_batch:
ALM-20260924
Product Type:
Switch Box
Configuration:
1-Gang
Series:
FiberglassBox
Department:
Electrical
Product Group:
Boxes & Enclosures
Product Subgroup:
Electrical Boxes
Product Material:
Fiberglass Reinforced Thermoset Polyester

Allied Moulded 9331-EWK – Frequently Asked Questions

1) Is 14 cubic inches enough box fill for a single switch with 12/2 Romex in and out?
The Allied Moulded 9331-EWK gives you 14 cubic inches of interior volume for one device. Box fill math is straightforward: each 12 AWG conductor counts 2.25 cubic inches, the device counts double the largest conductor (4.5), and all grounds together count once (2.25). Two 12/2 cables in and out gives four current-carrying conductors (9.0) plus device (4.5) plus grounds (2.25), for 15.75 cubic inches. That exceeds 14, so for 12 AWG with two cables you want a deeper box. With 14 AWG (2.0 per conductor) the same configuration works out to 14 cubic inches even, right at the limit.
2) Why use a fiberglass box instead of a standard PVC or metal single-gang box?
The 9331-EWK is moulded from fiberglass reinforced thermoset polyester rather than thermoplastic PVC or steel. Thermoset does not soften with heat the way thermoplastic does, and being non-metallic it will not corrode in damp locations like basements, garages, or laundry walls. Metal boxes still win where you need the box itself to carry a ground path or where physical abuse is severe; PVC is the cheaper choice for dry, ordinary interior work.
3) What are the outside dimensions of the Allied Moulded 9331-EWK?
It measures 2-3/8 x 3-1/4 x 2-1/2 inches, a standard single-gang footprint that takes ordinary one-gang switch and receptacle plates. The 2-1/2 inch dimension is the shallow direction, so check your stud cavity and any insulation or plumbing behind the drywall before you set it.
4) Is this box suitable for retrofit work in an existing finished wall?
The 9331-EWK is aimed at new construction and rough-in where you can fasten to a stud during framing, and it is also called out for renovation and remodel electrical work. For cutting into finished drywall with no stud access you generally want an old-work box with swing-out ears rather than a new-work box.
5) Will a fiberglass box like this work in a damp basement or garage wall?
Corrosion resistance is the main reason to pick it. Fiberglass reinforced thermoset polyester does not rust and resists moisture and impact, which is why it gets specified over steel in basements, garages, and utility spaces. It is not a substitute for a listed weatherproof outdoor enclosure with a gasketed cover in wet locations.
6) Can I use the 9331-EWK for a single receptacle as well as a switch?
Yes. It is a one-gang residential switch and receptacle box, so a single switch, single duplex receptacle, dimmer, or any other one-gang device mounts in it the same way.
7) What is the exact part number to order this Allied Moulded fiberglass switch box?
Order it as Allied Moulded 9331-EWK, part of the FiberglassBox line. That is the manufacturer part number for the 1-gang, 14 cubic inch version, and it ships as a single model with no finish or size options to specify.
How fast can I get the Allied Moulded 9331-EWK delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Allied Moulded 9331-EWK come with a warranty?
Absolutely. The Allied Moulded 9331-EWK is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Allied Moulded 9331-EWK?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Allied Moulded 9331-EWK from ZenSupply?
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