Sargent 351-L Retrofit Mounting Plate for LCN 4040 Closer – EN (Aluminum) Finish
The Sargent 351-L (351L) LCN 4040 Retrofit Mounting Plate is a factory-engineered adapter plate that allows a direct body swap from an LCN 4040 series closer to a Sargent 351 Powerglide closer — without cutting new mounting holes in the door face. Only the arm bracket requires new holes, making this one of the cleanest, lowest-disruption closer upgrades available for commercial doors carrying an existing LCN 4040 installation.
This plate is non-handed, so a single part number serves both left-hand and right-hand doors. The EN finish (ANSI/BHMA 689 — aluminum powder coat) matches standard aluminum-finish closer hardware and suits aluminum storefront, hollow metal, and painted steel door applications.
Why Upgrade from LCN 4040 to Sargent 351?
The Sargent 351 Powerglide is a full rack-and-pinion, adjustable-size (1–6) commercial closer with ADA-compliant closing force capability. Its one-piece die-cast aluminum alloy body, captivated valve adjustments, and interchangeable arm system make it a robust, field-serviceable choice. The 351-L retrofit plate bridges the existing LCN 4040 door-prep footprint so facilities can transition to the Sargent platform without patching or re-templating the door.
Compatible Closer Arms
The 351-L is compatible with three Sargent 351 arm configurations:
- O — Regular Arm Mounting (standard pull-side application)
- P9 — Regular Duty Parallel Arm Mounting (push-side, narrow profile)
- P10 — Heavy Duty Parallel Arm Mounting (push-side, high-traffic or wide doors)
Note: New mounting holes are required for the arm bracket only — the closer body footprint reuses existing LCN 4040 door holes.
Typical Applications
- Commercial office buildings replacing aging LCN 4040 closers without door repair
- Facility maintenance upgrades on hollow metal and aluminum doors
- Retrofit projects where original door prep is LCN 4040 and a Sargent 351 is the specified replacement closer
- Institutional and educational buildings standardizing on Sargent 351 Series hardware
Technical Details
| Feature | Details |
|---|---|
| Model Number | 351-L (351L) |
| Manufacturer | Sargent Manufacturing |
| Product Type | LCN 4040 Retrofit Mounting Plate |
| Compatible Closer Body | Sargent 351 Powerglide Series |
| Replaces / Fits Existing Prep | LCN 4040 Series door mounting footprint |
| Handed | Non-handed (universal) |
| Compatible Arms | O (Regular Arm), P9 (Regular Duty Parallel Arm), P10 (Heavy Duty Parallel Arm) |
| New Holes Required | Arm bracket only — closer body holes reuse existing LCN 4040 prep |
| Finish | EN — Aluminum Powder Coat (ANSI/BHMA 689) |
| Order Format | 351-L x EN |
| Product Category | Closer Parts / Mounting Plates |
Need this plate in a different finish, or looking to quote the complete Sargent 351 closer package for your project? Contact DoorwaysPlus for availability, volume pricing, and compatible 351 Series accessories.
| Brand | Sargent |
| General - US Finishes | EN - Aluminum Enamel |
| Series | Sargent - 351 Series |
| Closer Part Type | Drop Bracket |
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