Nsi Industries 1670 4-inch Steel Penny Knockout Seal

Product Description

The NSI INDUSTRIES 1670 is a 4-inch steel penny knockout seal designed to close unused knockouts in electrical enclosures, junction boxes, and panel boxes. Fabricated from steel, it provides a durable, code-compliant closure that keeps the interior of the enclosure protected from debris, pests, and accidental contact with live conductors. This type of fitting is a standard consumable on residential and commercial electrical jobs. Electricians keep these on hand for any rough-in or service call where a knockout is opened but not used.

The 1670 is suited for use in electrical boxes, load centers, conduit bodies, and metal enclosures requiring a 4-inch knockout fill. It is installed wherever an unused 4-inch opening needs to be sealed per NEC requirements for enclosure integrity. Common applications include panel installations, junction box work, and equipment disconnect enclosures.

Key Features

• Steel construction for durability and code-compliant knockout closure
• 4-inch size fits standard 4-inch knockouts in electrical enclosures
• Penny-style design installs quickly without additional hardware
• Supports NEC requirements for closing unused enclosure openings

Compatibility

Designed as an OEM-style replacement and standard fill fitting for 4-inch knockouts in residential and commercial electrical enclosures, junction boxes, and load centers.

Installation Notes

Installed by licensed electricians during panel work, junction box rough-in, or service upgrades. Always de-energize the enclosure and verify the absence of voltage before opening any panel or box. Penny seals are typically pressed or tapped into place by hand or with a flat-faced punch. Work performed inside load centers must comply with applicable NEC requirements.

Technical Specifications

• Knockout Size: 4 inches
• Material: Steel
• Package Dimensions (L x W x H): 5.25 inches x 4.75 inches x 3.5 inches
• UPC: 78174701670

Standard Information

• Brand: NSI INDUSTRIES
• Manufacturer Part Number: 1670