Steel City 52-C-0 Square Box Plaster Ring 4 Inch 1 Gang

Product Description

The STEEL CITY 52-C-0 is a flat-type, one-gang square box plaster ring designed for use in electrical rough-in and finish work. Stamped from hot-rolled pre-galvanized AISI C-1008 steel meeting ASTM G90-U standards at 0.062 inches thick, it provides a durable, corrosion-resistant mounting surface for devices installed in 4-inch square outlet boxes. The quick-release locking mechanism allows fast inner-ring depth adjustment without removing the assembly. Adjustment screws are positioned outside the inner ring, preserving maximum interior capacity for devices. A measured rule molded into the inner ring supports accurate pre-fab settings during pre-drywall installations.

This plaster ring is suited for residential and light commercial electrical installations where a 4-inch square box is used as the rough-in box and a single device — such as a switch, receptacle, or low-voltage plate — must be brought flush to the finished wall surface. The locking mechanism is positioned behind the outer ring, protecting it from router damage during drywall cutout and from excess mudding during finishing. Electricians use this ring in new construction and remodel work where precise device depth alignment is required before or after drywall installation.

Key Features

• Quick-release locking mechanism enables fast, tool-free depth adjustment of the inner ring
• Locking mechanism positioned behind outer ring — protected from router damage and excess joint compound
• Adjustment screws located outside the inner ring to preserve full device capacity inside the box
• Integrated measured rule on inner ring for accurate pre-fab depth setting in pre-drywall installations
• Hot-rolled pre-galvanized steel construction resists corrosion in standard wall cavity environments
• Flat-type profile accommodates flush device mounting on finished wall surfaces

Compatibility

Designed as an OEM-style replacement and standard-fit plaster ring for 4-inch square electrical outlet boxes requiring a one-gang, flat-type device cover.

Installation Notes

Installation is performed by licensed electricians in accordance with applicable NEC requirements. De-energize the circuit and verify zero voltage at the box before handling any conductors or securing the ring. Set inner-ring depth using the on-ring measurement rule before drywall is hung to reduce adjustment time at finish stage. Do not overtighten the locking mechanism — engage until the ring is firmly seated without deforming the box ears.

Technical Specifications

• Type: Flat
• Opening Type: 1 Device (1 Gang)
• Box Size: 4 inches
• Corner Type: Rounded
• Material: Hot Rolled Pre-Galvanized AISI C-1008, ASTM G90-U Steel
• Steel Thickness: 0.062 inches
• Color: Silver
• Approvals: UL 514A, CSA, FS W-J-800
• Standard Package: 25 per Carton
• Country of Origin: US

Standard Information

• Brand: STEEL CITY
• Manufacturer Part Number: 52-C-0