Radius Cover Plate for 19mm and 22mm RTD Lever on Backplate Lock 57mm

A 57mm Lock Cover Plate is the standard architectural solution for mid-to-high specification residential and commercial timber doors. Specifically engineered to match the 57mm PZ measurement—the UK’s most common standard for mortice sash locks and bathroom locks—this plate provides a professional, “snap-on” finish that conceals structural fixings and protects the door face.

Whether you are performing a new installation or a rapid refurbishment, these 57mm Lock Cover Plate offer a seamless way to upgrade your hardware to Grade 304 Stainless Steel while maintaining full compliance with fire safety and accessibility standards.

In the UK and many Commonwealth markets, 57mm centers are the benchmark for standard internal doors. The PZ measurement refers to the distance from the center of the handle spindle to the center of the rounded part of the Euro cylinder or the keyhole.

Key Performance Benefits

• Universal 57mm Fitment: This 57mm Lock Cover Plate is designed specifically for standard mortice sash locks and bathroom locks. It ensures that the handle and the lock cylinder align perfectly without the need for additional drilling or door modification.

• Tamper-Resistant Concealed Fixings: The decorative plate snaps over a metal sub-base, hiding all mounting screws. This creates a minimalist aesthetic and prevents unauthorized personnel from removing the hardware in public spaces like offices or schools.

• Dual-Bore Engineering: Designed to be versatile, these 57mm Lock Cover Plate accommodate both 19mm (Standard) and 22mm (DDA) lever diameters. An internal nylon bush ensures a smooth, rattle-free operation.

• Durable Construction: Stamped from Grade 304 Stainless Steel, these 57mm Lock Cover Plate are corrosion-resistant and suitable for high-traffic environments where frequent cleaning is required.

Technical Specifications of 57mm Lock Cover Plate

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Installation Pro-Tip: The “Sub-Chassis” Secret

When installing a 57mm plate, the secret to a perfectly straight finish lies in the sub-chassis.

1. Mount the sub-chassis loosely to the door leaf.

2. Insert your spindle and the lock cylinder (or thumbturn) to ensure the spacing is exactly 57mm.

3. Tighten the bolt-through fixings while the cylinder is in place to act as an alignment guide.

4. Once secured, “snap” the decorative cover over the base. You should hear a distinct click, indicating the plate is flush and secure.

This radius cover plate is designed for 19mm and 22mm RTD levers on a backplate with a 57mm lock cut-out. Made from high-quality, durable materials, it offers a practical solution for refurbishing or replacing door hardware while providing a neat and professional finish. The radius design adds a subtle, modern aesthetic while ensuring precise compatibility with standard lock lever and backplate fittings.

Ideal for residential and commercial doors, this cover plate is easy to install and helps protect your hardware while enhancing the overall appearance of your door. Combining strength, functionality, and a sleek radius design, the 57mm lock cover plate is a dependable choice for maintaining smooth, stylish, and long-lasting door operation.