Gardner Bender 16-Gauge Steel ...
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$54.53
$5.04
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Gardner Bender 16-Gauge Steel Knockout Seal with 3/8" Thread - Zinc-Plated Professional Installation

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Model: KO704

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

$54.53
$5.04
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Gardner Bender 16-Gauge Steel Knockout Seal with 3/8" Thread

Professional knockout sealing solution for electrical enclosures

The Gardner Bender knockout seal delivers reliable closure for unused knockouts in electrical boxes and enclosures. Constructed from 16-gauge cold-rolled galvanized steel with rust-proof protection, this professional-grade seal features a 3/8" thread design and zinc-plated screw and bar components for enhanced corrosion resistance and long-term durability in demanding electrical applications.

Professional Features & Benefits

  • 16-Gauge Steel Construction: Provides robust structural integrity and reliable sealing performance in electrical enclosures.
  • 3/8" Thread Design: Ensures secure installation and proper fit in standard knockout openings for professional applications.
  • Zinc-Plated Components: Screw and bar feature zinc plating for enhanced corrosion resistance and extended service life.
  • Cold-Rolled Galvanized Steel: Rust-proofed material construction delivers superior protection against environmental factors and moisture.
  • Embossed Self-Centering Design: Quick self-centering feature in unused knockouts ensures proper alignment and professional installation.
  • Single Screw Installation: One screw holds seal securely in place, simplifying installation process and reducing installation time.
  • Dual Installation Options: Fast and easy installation from inside or outside of electrical box for installation flexibility.

Technical Specifications

  • Each In Package Height In: 3.25
  • Each In Package Length Depth In: 2.25
  • Each In Package Weight Oz: 31.4
  • Each In Package Width In: 2.25

Professional Applications

  • Electrical Panel Installations
  • Commercial Electrical Enclosures
  • Industrial Control Boxes
  • Residential Service Panels
  • Junction Box Sealing
  • Maintenance and Retrofit Projects
  • Code Compliance Applications

Why Choose Gardner Bender Quality?

Gardner Bender knockout seals combine professional-grade materials with practical design features for reliable electrical enclosure sealing. The rust-proofed galvanized steel construction and zinc-plated components ensure long-term performance, while the embossed self-centering design and marked sizing provide professional installation efficiency and code compliance in demanding electrical applications.

Manufacturer Resources

Product Specs

Each In Package Height In :
3.25
Each In Package Length Depth In :
2.25
Each In Package Weight Oz :
31.4
Each In Package Width In :
2.25

Gardner Bender KO704 – Frequently Asked Questions

1) Can the Gardner Bender KO704 knockout seal be installed from outside the box, or do I need access inside?
Either way works. The KO704 installs from inside or outside the electrical box, which is what makes it usable on a panel already mounted to a wall where you cannot get behind the opening. One screw tightens it down, and the embossed self-centering design pulls it into alignment in the knockout as you draw it up.
2) What is a knockout seal used for in an electrical panel?
A knockout seal closes off an unused knockout opening in an electrical box, panel, or enclosure so the enclosure stays sealed after a punched-out hole is left empty. The Gardner Bender KO704 does this with a 16-gauge cold-rolled galvanized steel body and a single screw that draws a bar up behind the opening to clamp the seal in place. Typical uses are service panels, junction boxes, industrial control boxes, and retrofit work where a conduit run was removed.
3) What does the 3/8 inch thread on the Gardner Bender KO704 knockout seal refer to?
The 3/8 inch thread is the screw thread on the seal's fastener, the screw and bar assembly that clamps the seal against the knockout opening. The screw and bar are zinc plated for corrosion resistance. It is not a conduit trade size, so match the seal to the knockout hole diameter you are closing rather than to the thread callout.
4) Is a steel knockout seal better than a plastic snap-in plug for a commercial panel?
For commercial and industrial enclosures, a 16-gauge steel seal like the Gardner Bender KO704 gives you a metal closure with a screw-clamped bar behind the opening rather than a friction-fit plastic plug. Plastic snap-ins go in faster on light residential work, but they rely on the plug's tabs to stay put. The steel version holds mechanically with one screw and is galvanized against corrosion, which is why it shows up on service panels, control boxes, and junction box work.
5) Will a Gardner Bender steel knockout seal rust in a damp mechanical room or outdoor enclosure?
The body is rust-proofed cold-rolled galvanized steel and the screw and bar are zinc plated, so the whole assembly is protected against moisture and general corrosion. That is the reason to pick a galvanized steel seal over a bare steel one for damp basements, mechanical rooms, and enclosures exposed to weather.
6) What is the exact part number for the Gardner Bender 3/8 inch knockout seal?
Order it as Gardner Bender KO704. That is the manufacturer part number for the 16-gauge steel knockout seal with the 3/8 inch thread and zinc-plated screw and bar.
7) How is the Gardner Bender KO704 knockout seal packaged and how much does it weigh?
The KO704 ships in a package measuring 3.25 by 2.25 by 2.25 inches at 31.4 ounces, which points to a multi-piece pack rather than a single seal. Worth knowing if you are stocking a truck or a maintenance crib and want a quantity on hand for retrofit work.
How fast can I get the Gardner Bender KO704 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 Gardner Bender KO704 come with a warranty?
Absolutely. The Gardner Bender KO704 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 Gardner Bender KO704?
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 Gardner Bender KO704 from ZenSupply?
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