Best 2-Inch Knockout Plugs for Electrical Boxes: Top 5 Options
Finding a reliable 2-inch knockout plug is essential for protecting wires, reducing drafts, and keeping electrical boxes dust-tight. This guide highlights five standout options, covering metal, nylon, and plastic plugs from trusted brands. Each product section includes a quick link to the Amazon listing, a product image, and a concise snapshot of key features to help you compare at a glance.
| Product | Brand | Material | Key Benefit |
|---|---|---|---|
| Morris 21795 Type S Knockout Seal | Morris | Steel with screw & bar | Secure, durable protection for exposed wires |
| Sepco SS60 Zinc Plated | Sepco | Zinc-plated steel | Flush installation, corrosion resistant |
| Hillman 58179 Nylon Knock Out Seal | Hillman | Nylon | Tool-free, corrosion resistant |
| Caplugs 2″ Flush Mount Plug | Caplugs | Polyethylene plastic | Cost-effective, easy to install |
| Airmont AP-12055 | Airmont Products | Galvanized steel | Airtight, dust-tight protection |
Morris 21795 Type S Knockout Seal
The Morris 21795 Type S Knockout Seal with Screw and Bar is designed for open box knockouts, providing protection for exposed wires in standard, airtight, and dust-tight configurations. The set screw/bar design ensures a secure hold and straightforward installation. Suitable for practical electrical box applications, this seal helps maintain safety and reliability by sealing unused holes and preventing debris ingress.
OZXNO 6 Pcs Plastic Hole Plugs
The OZXNO set includes six 2-inch plastic hole plugs with a snap-in locking design. Made from nylon plastic, these plugs are lightweight, insulated, flame retardant, and abrasion resistant. Their card-tooth design makes installation quick and tool-free, allowing for rapid coverage of round knockout holes while offering solid dust protection.
Sepco SS60 Zinc Plated Steel Flat Knockout Seal
The Sepco SS60 offers a flush installation profile with zinc-plated steel construction for 2-inch trade sizes. This knockout seal provides tight, durable coverage for unused holes, contributing to safer and more orderly electrical box interiors. Its flat design minimizes obstruction while maintaining a solid seal.
Hillman 58179 Nylon Knock Out Seal
The Hillman Group 58179 2-1/2-Inch Hole Nylon Knock Out Seal is designed for electrical assemblies to cover knockout holes easily by hand. Made from high-quality nylon, it delivers sturdy, reliable performance with corrosion resistance. Its tool-free installation offers a quick, reusable solution for maintaining a neat electrical box interior.
Caplugs 2″ Flush Mount Plug
Caplugs offers a 2-inch flush mount plastic body and sheet metal hole plug in a 10-pack. Designed for 0.03″-0.08″ panel thickness, it features a compact head diameter and overall height suitable for tight spaces. The polyethylene plastic construction provides cost-effective, simple protection for unused holes while maintaining a clean appearance.
Airmont AP-12055 Knockout Seal
The Airmont AP-12055 is a pre-assembled, 2-inch screw-and-bar knockout seal made from galvanized steel with a zinc coating. It provides an airtight, dust-tight seal to keep dust, moisture, and pests out of unused holes. The embossed design assists with easy centering, and the steel construction ensures durable performance in demanding environments.
Buying Guide
- Material considerations: Metal seals (steel, zinc-plated) offer high durability and robust seals, while nylon and polyethylene plugs reduce cost and weight and can be easier to install in light-duty applications.
- Installation method: Screw-and-bar designs hold securely for long-term use, whereas tool-free nylon plugs are ideal for quick, temporary or low-maintenance setups.
- Seal integrity: For environments with dust, moisture, or rodents, prioritize airtight and dust-tight ratings. Zinc coatings and embossed centering features improve longevity and seal quality.
- Size compatibility: Confirm the knockout size (2 inches in this guide) and panel thickness range to ensure a proper fit without over-compression or gaps.
- Quantity and cost: For multiple installations, consider multi-pack options to reduce purchasing overhead while ensuring consistent performance across boxes.
- Environmental factors: Choose corrosion-resistant materials for damp or outdoor-rated electrical boxes; flame-retardant plastic is beneficial for heat-prone areas.
- Replacement and reusability: Nylon plugs often allow for easy removal and reuse, while metal seals may be more permanent fixtures depending on the design.