Sargent 351-A Mounting Plate – Aluminum (EN) for 351 Series Door Closers

The Sargent 351-A Mounting Plate is a factory-engineered adapter plate designed to extend the versatility of the Sargent 351 Powerglide Series surface door closer in two common real-world conditions: doors with a narrow top rail (minimum 2-3/8" top rail required) and top jamb mounting with limited frame clearance (minimum 1-3/4" frame clearance). Finished in EN (Aluminum powder coat, ANSI/BHMA 689), this plate is non-handed and coordinates seamlessly with the standard 351 Series aluminum finish.

When a door's top rail is too shallow to accept direct fastening of the closer body — a frequent condition on hollow metal doors, glass-lite doors, and narrow-stile commercial doors — the 351-A provides the additional bearing surface and correct hole pattern to complete the installation without fabricating custom adapters or relocating existing door prep holes.

Key Benefits

• Narrow top rail solution: Enables standard or top jamb mounting on doors with as little as 2-3/8" of usable top rail — a common challenge on commercial hollow metal and aluminum-framed doors.
• Low-clearance top jamb mounting: Supports top jamb installation with a minimum 1-3/4" frame clearance, addressing tight-clearance frame conditions without additional blocking or shimming.
• Non-handed: A single SKU works for both left-hand and right-hand openings — simplifies procurement and reduces inventory.
• Finish-matched: EN (aluminum powder coat / ANSI 689) matches the standard aluminum finish of the 351 closer body and arms for a clean, consistent appearance.
• Direct factory fit: Engineered specifically for the 351 Series — no field modification required; accepts standard 351 machine screw fastening pattern.

Typical Applications

• Commercial hollow metal doors with narrow top rails (2-3/8" minimum)
• Top jamb mounting where frame soffit clearance is limited to 1-3/4"
• Retrofit installations where direct door mounting is not feasible due to glazing, reinforcement, or rail geometry
• Schools, offices, healthcare facilities, and any commercial opening using the Sargent 351 Powerglide closer

Ordering Format

Order as: 351-A x finish (example: 351-A EN for aluminum powder coat). Non-handed — no hand designation required. Compatible with standard and top jamb 351 Series mounting configurations.

Technical Details

The Sargent 351-A EN Mounting Plate is a high-performance commercial door closer accessory specifically engineered to solve complex installation challenges on narrow-style doors and frames. This heavy-duty plate is required when mounting a Sargent 351 Series Powerglide® Closer in environments where standard mounting patterns are restricted by architectural design. By providing a reinforced and repositioned mounting surface, the 351-A allows for a secure Regular Arm (Pull Side) installation on doors with a minimum top rail of only 2-3/8", or a Top Jamb (Push Side) installation with as little as 1-3/4" of frame clearance.

Finished in EN Sprayed Aluminum, this mounting plate is a critical structural solution for modern aluminum storefronts and glass-heavy doors that prioritize aesthetics but require the durability of a Grade 1 door closer. Without this plate, a high-traffic entrance with a narrow top rail would be susceptible to hardware "pull-out" or operational failure. The non-handed design of the 351-A ensures it can be utilized for left-hand or right-hand applications, making it a versatile facility maintenance solution that preserves the lifecycle of the door closer while ensuring the opening remains fully compliant with ADA accessibility and Life Safety standards.

Mechanical Utility & ANSI Function Summary

The 351-A Mounting Plate serves as a vital structural bridge that adapts the heavy-duty mechanics of the Sargent 351 closer to non-standard frame and door geometries:

• Top Rail Expansion: Effectively "lowers" the mounting pattern, allowing a full-sized Powerglide® closer to fit on doors with a significantly reduced top rail.
• Low Ceiling Optimization: Solves "Top Jamb" mounting conflicts where the ceiling height would otherwise strike the closer body or arm.
• Force Distribution: By utilizing a larger footprint and specialized fastener locations, the plate acts as a stabilization solution, preventing the closer from vibrating loose in high-frequency commercial environments.
• ANSI/BHMA Grade 1 Support: When paired with the 351 series, this plate maintains the hardware’s ANSI/BHMA A156.4 Grade 1 certification, the industry's highest rating for durability, ensuring the door can withstand over two million opening cycles.

[Image showing a top jamb application of the Sargent 351 series closer utilizing a drop plate for low-clearance frames]

Technical Specifications

Engineered Solutions for Modern Storefronts

The Sargent 351-A EN provides targeted mechanical and logistical solutions for glazing contractors and facility managers:

• Narrow-Stile Aluminum Solution: Modern storefront doors often lack the 4" to 5" of top rail required for a standard closer mount. The 351-A is the primary architectural solution that enables the use of heavy-duty hardware without compromising the door's glass-heavy design.
• Overhead Holder Compatibility: This plate is a frequent integration solution for doors that utilize auxiliary overhead door holders, providing the necessary clearance to ensure both pieces of hardware operate without interference.
• Corrective Retrofit Strategy: In renovation projects where original frames were not prepared for closer mounting, the 351-A acts as a retrofit solution, covering old holes and providing a fresh, secure mounting surface that meets current fire and safety codes.
• Enhanced Door Control: By ensuring a perfectly level and rigid mount, the 351-A serves as a performance solution, preventing the hydraulic "chatter" or uneven closing speeds caused by a closer body that is slightly tilted on an uneven rail.
• Aesthetic Consistency: The EN finish provides a high-durability, color-matched facade that blends seamlessly with the closer body and aluminum door frame, offering a professional design solution that looks like an integral part of the original hardware.