Bridgeport Fittings 1691 Steel Knockout Hole Plug 1/2 Inch

Product Description

The BRIDGEPORT FITTINGS 1691 is a 1/2 inch steel knockout hole plug designed to seal unused knockout openings in electrical boxes and enclosures. It installs without tools — simply press or hammer the plug into place from outside the box. Rated for both indoor and outdoor use, this plug provides a secure, lasting closure that keeps debris, moisture, and pests out of the enclosure. Electricians and maintenance technicians reach for this type of plug during panel work, junction box installations, and enclosure modifications where unused knockouts must be closed per NEC requirements.

This plug is suited for residential and commercial electrical applications wherever a 1/2 inch knockout opening is left unused. Common install scenarios include service panels, junction boxes, conduit bodies, and weatherproof enclosures. Its outdoor rating makes it appropriate for exterior installations where environmental exposure is a factor. The press-in design speeds up the work when closing multiple knockouts on a single enclosure.

Key Features

• Seals 1/2 inch knockout openings in electrical boxes and enclosures
• Rated for indoor and outdoor use
• Press-fit or hammer installation — no tools required
• Steel construction for durable, long-term closure
• Helps meet NEC requirements for closing unused knockouts

Compatibility

Designed as an OEM-style replacement and standard fitment for 1/2 inch knockout openings in residential and commercial electrical boxes and enclosures.

Installation Notes

Installation is performed by a licensed electrician or qualified maintenance technician. De-energize the enclosure and follow OSHA lockout/tagout procedures before working inside any electrical box. Position the plug over the knockout opening from the exterior of the box and apply firm hand pressure or use a rubber mallet to seat it fully. Verify the plug is flush and fully seated before returning the enclosure to service.

Technical Specifications

• Knockout Size: 1/2 inch
• Material: Steel
• Application: Indoor and Outdoor

Standard Information

• Brand: BRIDGEPORT FITTINGS
• Manufacturer Part Number: 1691