A red head is the small red plastic anti-short bushing slipped between the conductors and the cut armor of AC cable, and often MC, before the connector goes on. It protects the insulation where the armor was cut and the wires bend into the box. Code requires them on AC cable, and inspectors look for the red lip showing inside the box. The same nickname also refers to a well-known brand of concrete wedge anchor, so context matters on the order sheet.
No red heads in any of these BX connectors, pull them apart, the inspector will fail the whole floor.
Also heard as
- redhead
- anti-short bushing
- anti-short
Related terms
BX
Trade name used for armored cable: insulated conductors inside a spiral metal jacket.
MC cable
Metal-clad cable: insulated conductors, including a green ground, inside interlocked aluminium or steel armor.
Tapcon
Blue hardened screw that cuts its own thread in a drilled hole in concrete or block, named for its brand.