---
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: "€ 31.85"
currency: EUR
in_stock: true
reviews_count: 5
category: "Prime Line"
url: https://www.desertcart.nl/products/330774912-prime-line-defender-security-u-9551-1-3-4-in
store_origin: NL
region: Netherlands
---

# Fits 1-3/4" thick doors precisely Anti-forced entry reinforcement Pre-punched for easy install 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:** € 31.85
**Availability:** ✅ In Stock

## Summary

> 🔐 Lock down your peace of mind with sleek, solid security.

## 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?** € 31.85 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/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

- • **Fortify Your Entry Point:** Reinforces the vulnerable latch area to prevent break-ins and forced entry.
- • **Precision Fit for Security:** Designed specifically for 1-3/4 inch thick doors with 2-1/8 inch bore and 2-3/8 inch backset for seamless integration.
- • **Durable Stainless Steel Build:** Crafted from solid alloy steel with a sleek stainless finish that resists wear and tampering.
- • **Trusted Quality & Performance:** Backed by over 1,000 positive reviews and a 4.4-star rating, a must-have for millennial professionals valuing safety and style.
- • **Quick & Hassle-Free Installation:** Comes with all mounting hardware and pre-punched holes for a fast, no-fuss setup.

## Overview

The PRIME-LINE Defender Security U 9551 is a solid alloy steel door reinforcer designed to prevent forced entry by strengthening the latch area of 1-3/4 inch thick doors. Featuring a precise fit for doors with a 2-1/8 inch bore and 2-3/8 inch backset, it includes all necessary hardware and pre-punched holes for easy installation. Its durable stainless steel finish ensures long-lasting protection, making it a top-rated choice for residential and commercial door security.

## 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: Measure the hole first from edge to center and see if it is the right one! - It was to short did not reach the pad lock hole no good for me,measure from edge of door to center of hole does not measure the same at all sorry it stainless steel nice nothing els to say sorry
Review: de excelente calidad - Cumplio las expectativas de mi compra y es un producto de excelente calidad

## 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 | #175,488 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #837 in Door Latches & Bolts |
| Brand | PRIME-LINE |
| Brand Name | PRIME-LINE |
| Color | Stainless Steel |
| Country of Publication | USA |
| Customer Reviews | 4.4 out of 5 stars 1,061 Reviews |
| Finish Types | Stainless Steel |
| Global Trade Identification Number | 00049793195517 |
| Included Components | Lock and Door Reinforcer |
| Item Dimensions | 9.8 x 4.4 x 22.9 centimeters |
| Item Type Name | Lock and Door Reinforcer |
| Item Weight | 0.8 Pounds |
| Item dimensions L x W x H | 9.8 x 4.4 x 22.9 centimeters |
| Lock Type | Deadbolt |
| Lock type | Deadbolt |
| Manufacturer | Prime-Line Products |
| Material | Alloy Steel |
| Material Type | Alloy Steel |
| Model Number | U 9551 |
| 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)

## Customer Reviews

### ⭐ Measure the hole first from edge to center and see if it is the right one!
*by A***R on 30 September 2018*

It was to short did not reach the pad lock hole no good for me,measure from edge of door to center of hole does not measure the same at all sorry it stainless steel nice nothing els to say sorry

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

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

### ⭐⭐⭐⭐⭐ good quality
*by R***S on 16 December 2025*

really made a big difference on my garage

## 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)

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.nl/products/330774912-prime-line-defender-security-u-9551-1-3-4-in](https://www.desertcart.nl/products/330774912-prime-line-defender-security-u-9551-1-3-4-in)

---

*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-02-21*