Hoffman AS100-AS300 Hol-Sealer...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$15.08
Hoffman AS100-AS300 Hol-Sealers Steel Hole Seal, 1" to 3"

Hoffman AS100-AS300 Hol-Sealers Steel Hole Seal, 1" to 3"

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Model: AS100

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

$15.08
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Hoffman AS100 Hole Seal Plug for Electrical Enclosures

The Hoffman AS100 Hole Seal is a purpose-built hole sealer designed to close off unused openings, cutouts, and knockouts in electrical enclosures, panels, and equipment housings. Identified by its HOL-SEALERS HOLE SEAL designation, the AS100 provides a simple, reliable way to restore the integrity of an enclosure wall once a hole is no longer needed for conduit entry, wiring, or hardware mounting. Electrical contractors and panel builders rely on hole seals like the AS100 to maintain a clean, finished enclosure interior and to help keep out dust, debris, and unwanted intrusion through openings that would otherwise remain exposed.

Key Features

  • Hole Sealing Function: Engineered specifically to plug and seal unused holes, cutouts, and knockouts in electrical enclosures and panel walls.
  • Hoffman Build Quality: Manufactured by Hoffman, a recognized name in enclosure and panel accessory hardware for industrial and commercial electrical work.
  • Simple Installation: Designed as a straightforward, install-in-place hole seal that does not require special tools for placement into an existing opening.
  • Clean Finished Appearance: Helps restore a neat, professional look to an enclosure once a knockout or hole is no longer required.
  • Enclosure Protection: Helps reduce the entry path for dust and debris through an unused opening in the enclosure wall.
  • Model AS100: Part of the Hoffman HOL-SEALERS hole seal product line, identified under model designation AS100.

Technical Specifications

  • Model: AS100
  • Product Line: Hoffman HOL-SEALERS
  • Refer to manufacturer documentation for complete dimensional and material specifications.

Typical Applications

  • Sealing Unused Knockouts in Electrical Enclosures
  • Closing Off Redundant Cutouts After Panel Modifications
  • Finishing Enclosure Walls in Industrial and Commercial Panel Builds
  • Maintenance and Retrofit Work Where Openings Are No Longer Needed
  • General Enclosure Housekeeping in Electrical Rooms and Equipment Rooms

Why Hoffman?

Hoffman is an established supplier of enclosure hardware and accessories used throughout industrial and commercial electrical installations. The AS100 Hole Seal reflects that same practical, purpose-built approach, offering electrical professionals a dependable way to close unused openings and keep enclosures organized and protected. Choosing a Hoffman hole seal means choosing a component made to work seamlessly within the broader Hoffman enclosure ecosystem for panel builders and maintenance teams alike.

Manufacturer Resources

Product Specs

Department:
Electrical
list_batch:
HOF-20260924
Product Subgroup:
Enclosure Accessories
Product Type:
Gland Plate & Entry Seal
Product Group:
Boxes & Enclosures

Hoffman AS100 – Frequently Asked Questions

1) What sizes do Hoffman Hol-Sealers hole seals come in?
Hoffman Hol-Sealers are offered in five sizes matched to standard conduit knockouts: 1 inch (AS100), 1-1/4 inch (AS125), 1-1/2 inch (AS150), 2 inch (AS200) and 3 inch (AS300). Size the seal to the knockout trade size you are closing, not to the conduit that used to be in it.
2) I have an unused 1-1/2 inch knockout in a panel enclosure. Which Hoffman part closes it?
The AS150 Hol-Sealer is the 1-1/2 inch size. It drops into the existing opening and closes it off without special tools, restoring the enclosure wall and cutting the path for dust and debris through the hole.
3) Can I use a Hoffman Hol-Sealer to seal a knockout in a non-Hoffman enclosure?
Yes, as long as the opening is one of the standard trade sizes the AS series covers, 1 through 3 inches. Knockout sizes in steel enclosures are standardized, so the seal is matched to the hole diameter rather than to the brand of box. For Hoffman panels it is part of the same accessory line, so it suits the rest of the enclosure hardware.
4) Is a Hol-Sealer hole seal the right fix after modifying a panel, or should I replace the enclosure wall?
For a redundant cutout or knockout left behind after a panel modification, a Hol-Sealer is the normal fix: it plugs the opening in place and gives a finished interior and exterior appearance again. Hoffman lists exactly that use, along with maintenance and retrofit work where openings are no longer needed. It is a sealing accessory for a round knockout of a standard trade size, so an irregular or oversized cutout that does not match 1, 1-1/4, 1-1/2, 2 or 3 inch is not what these are for.
5) Do Hoffman AS-series hole seals need a punch or special tool to install?
No. The Hol-Sealers are install-in-place seals that go into an existing opening without special tools, which is why panel builders and maintenance electricians keep an assortment of the sizes on the truck.
6) Will a Hol-Sealer keep dust out of an electrical enclosure?
It closes the opening and reduces the entry path for dust and debris through an unused hole, which is the stated purpose. Treat it as a hole closure for enclosure housekeeping and intrusion reduction rather than as a rated environmental seal, since no enclosure type rating is attached to the AS series.
7) What is the largest knockout a Hoffman AS hole seal will close?
Three inches, using the AS300. Above that size the AS series does not go, so an opening larger than 3 inches needs a blanking plate or filler panel rather than a Hol-Sealer.
How fast can I get the Hoffman AS100 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 Hoffman AS100 come with a warranty?
Absolutely. The Hoffman AS100 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 Hoffman AS100?
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 Hoffman AS100 from ZenSupply?
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