---
product_id: 330774912
title: "PRIME-LINE Defender Security U 9551 1-3/4 In. x 9 In. Thick Solid Brass Lock and Door Reinforcer, 2-1/8 In. Single Bore, 2-3/8 In. Backset (Single Pack)"
brand: "prime-line"
price: "353.88 DT"
currency: TND
in_stock: true
reviews_count: 5
category: "Prime Line"
url: https://www.desertcart.tn/products/330774912-prime-line-defender-security-u-9551-1-3-4-in
store_origin: TN
region: Tunisia
---

# Solid brass lock reinforcer Pre-punched for easy install Anti-forced entry protection PRIME-LINE Defender Security U 9551 1-3/4 In. x 9 In. Thick Solid Brass Lock and Door Reinforcer, 2-1/8 In. Single Bore, 2-3/8 In. Backset (Single Pack)

**Brand:** prime-line
**Price:** 353.88 DT
**Availability:** ✅ In Stock

## Summary

> 🛡️ Lock down your peace of mind with solid brass strength!

## Quick Answers

- **What is this?** PRIME-LINE Defender Security U 9551 1-3/4 In. x 9 In. Thick Solid Brass Lock and Door Reinforcer, 2-1/8 In. Single Bore, 2-3/8 In. Backset (Single Pack) by prime-line
- **How much does it cost?** 353.88 DT with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/330774912-prime-line-defender-security-u-9551-1-3-4-in)

## Best For

- prime-line enthusiasts

## Why This Product

- Trusted prime-line brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Effortless Installation:** Includes all mounting hardware and pre-punched holes for a quick, hassle-free upgrade to your door security.
- • **Fortify Your Entry Point:** Reinforces the vulnerable latch area to prevent forced entry, securing your home or office with confidence.
- • **Premium Solid Brass Build:** Crafted from durable solid brass alloy steel for long-lasting strength and corrosion resistance.
- • **Sleek Stainless Steel Finish:** Natural brass finish blends with your door hardware, adding a subtle yet powerful layer of protection.
- • **Precision Fit for Standard Doors:** Designed specifically for 1-3/4 inch thick doors with 2-1/8 inch bore and 2-3/8 inch backset for seamless integration.

## Overview

The PRIME-LINE Defender Security U 9551 is a solid brass lock and door reinforcer designed to enhance door security by reinforcing the latch area against forced entry. It fits 1-3/4 inch thick doors with a 2-1/8 inch bore and 2-3/8 inch backset, comes with all necessary mounting hardware, and features a pre-punched design for easy installation. Its durable alloy steel construction and sleek brass finish provide both strength and style, making it an essential upgrade for residential and commercial entry doors.

## Description

Defender Security U 9551 Stainless Steel Lock and Door Reinforcer assists in preventing forced entry by reinforcing the weak spot of an entry door. It can be used to reinforce and repair both metal and wood doors. Made of solid brass construction, the lock reinforcer plate comes finished in brass. All the necessary mounting hardware is included for a quick and easy installation. The lock reinforcement plate is pre-punched for mounting. The reinforcer is designed for 1-3/8 inch thick doors that have mortise or drive-in latches. It features one 2-1/8 inch bore with a 2-3/8 inch backset. The door reinforcer is recessed. Please refer to the line art drawing for dimensions and compare to your needs before purchasing (Not Universal).

Review: de excelente calidad - Cumplio las expectativas de mi compra y es un producto de excelente calidad
Review: Protége bien la porte contre inteuision - Excellent

## Features

- ADDED SECURITY – Prevent forced entry by reinforcing the weak spot of your door with the non-recessed door lock reinforcer; use to reinforce and repair both metal, fiberglass and wood doors when the latch area has been compromised
- BUILT TO LAST – Made of stainless steel, the door lock reinforcement plate comes in a natural finish to fit over a single bore hole on your door
- EASY INSTALLATION – All the necessary mounting hardware is included with the lock reinforcement plate for a quick and easy installation; the door reinforcer plate is pre-punched for mounting. Remove the protective film after installation
- DIMENSIONS – The door lock reinforcement plate is designed for 1-3/4 inch thick doors only that have a 2-1/8 inch bore hole through the door, with a 2-3/8 inch backset from the edge of the door to the center of the bore holes
- NOTE – Make sure to dry fit the 3-7/8 inch wide by 9 inch tall with a 0.03 inch thickness door lock reinforcer before permanently installing and refer to the line art drawing and compare with your needs before purchasing
- Used to reinforce and repair doors to aide in preventing forced entry
- Fits 1-3/4 in. thick doors, 2-1/8 in. bores, 2-3/8 in. backset, 3-7/8 in. width x 9 in. height
- Stainless steel

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B000OFTIL8 |
| Additional Features | Anti-Forced Entry |
| Best Sellers Rank | #132,926 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #626 in Door Latches & Bolts |
| Brand | PRIME-LINE |
| Brand Name | PRIME-LINE |
| Color | Stainless Steel |
| Control Method | Touch |
| Customer Reviews | 4.4 out of 5 stars 1,098 Reviews |
| Finish Types | Stainless Steel |
| Global Trade Identification Number | 00049793195517 |
| Included Components | Lock and Door Reinforcer |
| Item Dimensions | 9.2 x 4.4 x 11.4 centimeters |
| Item Type Name | Lock and Door Reinforcer |
| Item Weight | 363 g |
| Item dimensions L x W x H | 9.2 x 4.4 x 11.4 centimeters |
| Lock Type | Deadbolt |
| Lock type | Deadbolt |
| Manufacturer | Prime-Line Products |
| Manufacturer Part Number | U 9551 |
| Material | Alloy Steel |
| Material Type | Alloy Steel |
| Model Name | Door guard |
| Model Number | U 9551 |
| Number of Pieces | 1 |
| Recommended Uses For Product | Reinforcing entry doors in residential and commercial buildings to prevent forced entry |
| Recommended uses for product | Reinforcing entry doors in residential and commercial buildings to prevent forced entry |
| Shape | shape |
| Special features | Anti-Forced Entry |
| Style Name | Slip On |
| UPC | 049793195517 |
| Unit Count | 1 Count |

## Product Details

- **Brand:** PRIME-LINE
- **Item dimensions L x W x H:** 9.8 x 4.4 x 22.9 centimeters
- **Lock type:** Deadbolt
- **Material:** Alloy Steel
- **Special features:** Anti-Forced Entry

## Images

![PRIME-LINE Defender Security U 9551 1-3/4 In. x 9 In. Thick Solid Brass Lock and Door Reinforcer, 2-1/8 In. Single Bore, 2-3/8 In. Backset (Single Pack) - Image 1](https://m.media-amazon.com/images/I/51XtMzs6xqL.jpg)
![PRIME-LINE Defender Security U 9551 1-3/4 In. x 9 In. Thick Solid Brass Lock and Door Reinforcer, 2-1/8 In. Single Bore, 2-3/8 In. Backset (Single Pack) - Image 2](https://m.media-amazon.com/images/I/61pBpl6nweL.jpg)
![PRIME-LINE Defender Security U 9551 1-3/4 In. x 9 In. Thick Solid Brass Lock and Door Reinforcer, 2-1/8 In. Single Bore, 2-3/8 In. Backset (Single Pack) - Image 3](https://m.media-amazon.com/images/I/61UJR6yOy5L.jpg)
![PRIME-LINE Defender Security U 9551 1-3/4 In. x 9 In. Thick Solid Brass Lock and Door Reinforcer, 2-1/8 In. Single Bore, 2-3/8 In. Backset (Single Pack) - Image 4](https://m.media-amazon.com/images/I/71UrKVyEOrL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ de excelente calidad
*by A***R on 8 January 2023*

Cumplio las expectativas de mi compra y es un producto de excelente calidad

### ⭐⭐⭐⭐⭐ Protége bien la porte contre inteuision
*by C***N on 7 April 2026*

Excellent

### ⭐⭐⭐⭐⭐ Great adition to door
*by I***M on 10 March 2025*

Quality: The plate is high quality, with clean edges and precise dimensions. Functionality: As advertised, the product effectively reinforces the existing door set. After my wife's constant complaints, I purchased this item to prevent greasy fingerprints from accumulating on the door due to frequent entry and exit from the garage after working on projects. Now I can easily wipe off greasy marks and have a happy spouse. The installation required the mortising of the area behind the faceplate to ensure that the reinforcing plate sits flush with the door’s edge. Your installation may also require mortising the striker side of the jam. Tip: Remove the adhesive plastic coating from the plate after fitting and before final assembly.

## Frequently Bought Together

- Prime-Line U 9551 Stainless Steel Lock and Door Reinforcement Plate for 1-3/4 In. Thick Doors, Stainless Steel Finish (Single Pack)
- Prime-Line U 9476 Maximum Security Latch Strike, 1-1/4 In. x 7-7/8 In., Steel, Chrome Plated (Single Pack)
- Prime-Line U 9585 Stainless Steel Lock and Door Reinforcement Plate for 1-3/8 In. Thick Doors, Stainless Steel Finish (Single Pack)

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*Product available on Desertcart Tunisia*
*Store origin: TN*
*Last updated: 2026-07-08*