1" Knockout Bushing
Metal Stud Knockout Bushing
Our Non-metallic Knockout Bushing for metal studs is perfect for adding protection to irregularly shaped holes in metal studs. Also by adding a metal stud knockout bushing, you will increase structural support for weakening structural members.
This bushing fits in an existing irregular shaped hole in metal studs, alleviating the need to punch holes in metal studs, weakening the structural member. Use these bushings to comply with paragraph 300.4(b)(1) of the 2014 NEC code which states that: "In both exposed and concealed locations where non-metallic-sheathed cables pass through either factory or field punched, cut, or drilled slots or holes in metal members, the cable shall be protected by bushings or grommets covering all metal edges and securely fastened in the opening prior to installation of the cable."