Metallics Knock-out Seal 3/4" ...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$51.59
$2.69
Metallics Seal 3/4 K-O Seal St-zn

Metallics Knock-out Seal 3/4" 3-Piece Steel Zinc Quick-Seal

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Model: 75KOS
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$51.59
$2.69
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Metallics Industries Knock-out Seal 3/4" 3-Piece Steel Zinc Quick-Seal

Professional Electrical Panel Box Sealing Solution

The Metallics Industries Knock-out Seal 3/4" delivers exceptional performance and reliability for electrical panel box installations and conduit system sealing. This steel knock-out seal with zinc finish provides dependable electrical sealing solutions designed for professional contractors, electricians, and industrial technicians, offering the proven quality and precision engineering that professionals trust from a leading manufacturer of electrical hardware and industrial fasteners.

Professional Features & Benefits

Quick-Seal Performance

  • 3-Piece Quick-Seal Design - Provides fast and secure sealing of unused knock-out holes in electrical panel boxes with professional-grade steel construction and zinc finish protection
  • Size Stamped Identification - Clear 3/4" size marking stamped directly on seal ensures proper selection and installation verification for electrical code compliance
  • Steel Construction with Zinc Finish - Durable steel material with protective zinc coating delivers long-lasting corrosion resistance and reliable performance in electrical environments
  • Professional Quality Standards - Metallics Industries precision manufacturing ensures consistent dimensions and reliable sealing performance for critical electrical installations

Installation Efficiency

  • Quick Installation Process - 3-piece design allows for rapid installation without special tools, reducing labor time on electrical panel installations
  • Secure Panel Box Sealing - Effectively plugs unused knock-out holes to maintain electrical panel integrity and meet safety code requirements
  • Professional Packaging - Convenient bag packaging with 10-piece minimum order quantity ensures adequate supply for multiple installations

Technical Specifications

Material: Steel | Finish: Zinc | Type: 3-Piece Knock-Out Seal | Dimensions: 4" Length x 4" Width x 1" Height | Weight: 0.33 lbs | Number of Pieces: 3 | Pack Type: Bag | Product Family: Electrical Supplies | Product Group: Conduit Accessories | Field Application: Electrical, Plumbing, Heating and Air Conditioning Industries

Installation & Usage

  1. Verify the 3/4" knock-out hole size matches the stamped seal size marking for proper fit
  2. Clean the knock-out hole area of any debris or sharp edges that could interfere with sealing
  3. Insert the first piece of the 3-piece quick-seal system into the knock-out hole from the interior side
  4. Position the second piece on the exterior side of the panel box to sandwich the panel material
  5. Secure the third piece to complete the quick-seal assembly and ensure tight sealing
  6. Verify the seal is flush and secure with no gaps around the knock-out hole perimeter

Professional Applications

Ideal for:

  • Electrical Panel Installations - Sealing unused knock-out holes in electrical panel boxes, load centers, and distribution panels
  • Conduit System Maintenance - Plugging abandoned conduit entry points and maintaining electrical enclosure integrity
  • Commercial Electrical Work - Professional electrical installations requiring code-compliant sealing of unused openings
  • Industrial Control Panels - Sealing knock-out holes in motor control centers and industrial electrical enclosures
  • HVAC Electrical Connections - Sealing unused electrical connections in heating and air conditioning system installations
  • Plumbing System Electrical - Electrical panel modifications for plumbing system controls and monitoring equipment
  • Building Maintenance - Retrofitting and updating electrical panels with proper sealing of unused openings
  • Safety Code Compliance - Meeting electrical code requirements for sealed electrical enclosures and panel boxes

Steel and Zinc Finish Advantage

The steel construction provides exceptional strength and durability for long-term electrical installations, while the zinc finish offers superior corrosion resistance in various environmental conditions. This combination ensures reliable performance in electrical, plumbing, and HVAC applications where moisture and temperature variations are common, making it ideal for both indoor and outdoor electrical panel installations.

Why Choose Metallics Industries Quality?

Metallics Industries demonstrates unwavering commitment to precision manufacturing and quality control excellence in electrical hardware and industrial fasteners. Our professional-grade materials and protective finishes ensure reliable performance for contractors, electricians, and industrial professionals. With comprehensive testing protocols and superior material selection, Metallics Industries delivers trusted electrical hardware solutions for commercial, industrial, and construction applications, backed by engineering excellence and proven performance standards that professionals depend on for critical electrical installations.

Manufacturer Resources

Product Specs

Arra Compliant:
C
Buy American Compliant:
C
Country Of Origin:
MUL
Division:
Electrical H1
Field Application:
Electrical, Plumbing, Heating and Air Conditioning Industries
Language Code:
EN
Number Of Pieces:
3
Order Minimum Imperial:
10
Order Minimum Uom Imperial:
EA
Pack Type:
Bag
Product Family:
Electrical Supplies
Product Height:
1 in
Product Length:
4 in
Product Weight:
0.33 lbs
Product Width:
4 in
Sub Division:
Electrical-E H2
Product Type:
Knock-out seals
Product Group:
Conduit Accessories
Department:
Electrical
Product Subgroup:
Plugs and Seals
Type2:
3 Pieces Knock-Out Seal
Product Finish:
Zinc
Product Details:
3 Pieces Knock-Out Seal
Product Material:
Steel

Metallics 75KOS – Frequently Asked Questions

1) What size knock-out hole does the Metallics 75KOS seal fill?
The 75KOS fills a 3/4 inch knock-out. The size is stamped on the seal itself, so on a panel with mixed 1/2, 3/4 and 1 inch openings you can confirm you grabbed the right one before it goes in. Match the seal to the hole size, not to the conduit that used to be there.
2) How does a 3-piece knock-out seal install, and do I need tools inside the panel?
Three pieces sandwich the panel wall: one goes in from the interior side of the opening, the second seats on the exterior, and the third draws the assembly tight. No special tools, and no access needed beyond reaching both faces of the enclosure. That two-sided access is the catch worth checking first, since a knock-out on a wall-tight section of a load center can be hard to reach from behind.
3) Is the Metallics 3/4 inch knock-out seal steel or plastic, and will it hold up in a damp location?
Steel with a zinc finish, not plastic. The zinc coating is the corrosion resistance, which is why this style gets used on outdoor and unheated panel locations where a snap-in plastic plug would get brittle. If you are standardizing an MRO stock room, the steel version is the one that survives handling in a bin.
4) Is a knock-out seal only for electrical panels, or can I use it on HVAC and plumbing control enclosures?
Metallics lists the field application across electrical, plumbing, and heating and air conditioning work. Practically, any sheet metal enclosure with an unused 3/4 inch knock-out is fair game: load centers, distribution panels, motor control centers, and the control cabinets on HVAC equipment. The seal does not care what trade drilled the hole, only that it is 3/4 inch.
5) Is the Metallics 75KOS Buy American compliant for a government or institutional job?
Metallics flags the 75KOS as both Buy American compliant and ARRA compliant, with country of origin recorded as multiple. On federally funded work that pairing is what a procurement officer needs on the submittal, so it is worth capturing the compliance flags when you spec the part.
6) What is the difference between a 3-piece knock-out seal and a snap-in plug for an unused panel opening?
A 3-piece seal clamps the panel wall between an interior and an exterior component, so it stays put under vibration and cannot be pushed out from either side. A one-piece snap plug relies on friction against the hole edge alone. On a motor control center or any enclosure that sees movement, the mechanical clamp is the reason to reach for the 3-piece. For a dry interior panel that will never be touched again, a simpler plug does the job.
7) What does one Metallics 3/4 inch knock-out seal weigh, and how much bin space does a bag take?
Each seal is listed at 0.33 lbs, with product dimensions of 4 x 4 x 1 inches on the packaged record. Ten of them in a bag is a light, small item, easy to keep on the truck alongside other conduit accessories rather than ordering per job.
8) Do I need to deburr the knock-out before installing the seal?
Yes, clear the opening of debris and sharp edges first. A ragged knock-out left by pliers keeps the seal from seating flush, and the last step is checking there is no gap around the perimeter. Two minutes with a file saves a callback on an enclosure that was supposed to be closed up.
How fast can I get the Metallics 75KOS 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 Metallics 75KOS come with a warranty?
Absolutely. The Metallics 75KOS 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 Metallics 75KOS?
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 Metallics 75KOS from ZenSupply?
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