---
product_id: 294031248
title: "LOCTITE® SI 5900 | silicone-based| flange sealant |high resistance to oil| used in stamped sheet metal covers| metal, plastic, glass,ceramic substrates| does not shrink, compress, crack or relax"
brand: "loctite"
price: "$5.69"
currency: USD
in_stock: false
reviews_count: 5
url: https://www.desertcart.us/products/294031248-loctite-si-5900-silicone-based-flange-sealant-high-resistance-to
store_origin: US
region: United States of America
---

# Temp range -65°F to 500°F Multi-substrate adhesion (metal, plastic, glass) High oil resistance & non-corrosive LOCTITE® SI 5900 | silicone-based| flange sealant |high resistance to oil| used in stamped sheet metal covers| metal, plastic, glass,ceramic substrates| does not shrink, compress, crack or relax

**Brand:** loctite
**Price:** $5.69
**Availability:** ❌ Out of Stock

## Summary

> 🛠️ Seal like a pro, last like a legend.

## Quick Answers

- **What is this?** LOCTITE® SI 5900 | silicone-based| flange sealant |high resistance to oil| used in stamped sheet metal covers| metal, plastic, glass,ceramic substrates| does not shrink, compress, crack or relax by loctite
- **How much does it cost?** $5.69 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/294031248-loctite-si-5900-silicone-based-flange-sealant-high-resistance-to)

## Best For

- loctite enthusiasts

## Why This Product

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

## Key Features

- • **Oil-Resistant Armor:** Engineered to resist oil and corrosion, ensuring long-lasting flange protection in demanding environments.
- • **Instant Seal, Low Odor:** Provides rapid adhesion with a low-volatility, low-odor formula that’s safe and efficient for professional use.
- • **Unmatched Thermal Endurance:** Withstands extreme temps from -65°F to 500°F, keeping your seals intact no matter the heat or cold.
- • **Zero Shrinkage, Zero Worries:** Formulated to never shrink, compress, crack, or relax, guaranteeing a flawless, durable seal every time.
- • **Versatile Surface Compatibility:** Bonds seamlessly to metal, plastic, glass, and ceramic—perfect for diverse industrial applications.

## Overview

LOCTITE® SI 5900 is a premium silicone-based flange sealant designed for high resistance to oil and extreme temperatures (-65°F to 500°F). It offers superior flexibility and adhesion across multiple substrates including metal, plastic, glass, and ceramic. This non-corrosive, low-odor sealant ensures no shrinkage or cracking, making it ideal for stamped sheet metal covers and demanding industrial applications.

## Description

Superior flexibility and adhesion. Provides instant seal. Non-corrosive, low odor, and low volatility

Review: Worth the money - A bit pricey but does an excellent job. I used it for sealing an oil pan in a diesel engine.
Review: Very expensive but a very good product - I have used this on a couple Mercedes engine assemblies now. Timing Cover, Valve Covers, Oil Pan on these later Mercedes engines they are all sealed with this special silicone and no gaskets. I have read of other techs needing to re do the job due to leaks because they try to use lower quality silicone products. This one works well as intended. Costs a lot but works. The large tube is enough to do several engines. No leaks on my work so far.

## Features

- Capacity Vol. - 300 mL
- Temp. Range - -65.0 °F [Min], 500.0 °F [Max]
- Hardness - 35.0 Shore A
- Applications - Multi-Purpose
- Applicable Materials - Most Metals

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B002BWH0WQ |
| Best Sellers Rank | #181,393 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #2,493 in Universal Adhesives |
| Brand | Loctite |
| Brand Name | Loctite |
| Colour | As shown in the image |
| Compatible Material | Metal |
| Customer Reviews | 4.5 out of 5 stars 36 Reviews |
| Global Trade Identification Number | 00079340201668 |
| Included Components | 1 |
| Item Form | Paste |
| Manufacturer | Loctite |
| Manufacturer Part Number | 20166 |
| Material | As shown in the image |
| Material Type | As shown in the image |
| Model | 20166 |
| Net Quantity | 1 Count |
| Number of Items | 1 |
| Style | Compact |
| Style Name | Compact |
| Surface Recommendation | Metal |
| UPC | 079340201668 |
| Unit Count | 1 Count |

## Product Details

- **Colour:** As shown in the image
- **Brand:** Loctite
- **Liquid Volume:** 10.14 Fluid Ounces
- **Item Form:** Paste
- **Surface Recommendation:** Metal

## Images

![LOCTITE® SI 5900 | silicone-based| flange sealant |high resistance to oil| used in stamped sheet metal covers| metal, plastic, glass,ceramic substrates| does not shrink, compress, crack or relax - Image 1](https://m.media-amazon.com/images/I/71TbD3KjohL.jpg)
![LOCTITE® SI 5900 | silicone-based| flange sealant |high resistance to oil| used in stamped sheet metal covers| metal, plastic, glass,ceramic substrates| does not shrink, compress, crack or relax - Image 2](https://m.media-amazon.com/images/I/611m9PUgjpL.jpg)
![LOCTITE® SI 5900 | silicone-based| flange sealant |high resistance to oil| used in stamped sheet metal covers| metal, plastic, glass,ceramic substrates| does not shrink, compress, crack or relax - Image 3](https://m.media-amazon.com/images/I/61y+NLdkHWL.jpg)
![LOCTITE® SI 5900 | silicone-based| flange sealant |high resistance to oil| used in stamped sheet metal covers| metal, plastic, glass,ceramic substrates| does not shrink, compress, crack or relax - Image 4](https://m.media-amazon.com/images/I/71RTc94CP0L.jpg)
![LOCTITE® SI 5900 | silicone-based| flange sealant |high resistance to oil| used in stamped sheet metal covers| metal, plastic, glass,ceramic substrates| does not shrink, compress, crack or relax - Image 5](https://m.media-amazon.com/images/I/81rwmDuNvQL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Worth the money
*by E***A on 2 January 2024*

A bit pricey but does an excellent job. I used it for sealing an oil pan in a diesel engine.

### ⭐⭐⭐⭐⭐ Very expensive but a very good product
*by M***D on 23 March 2023*

I have used this on a couple Mercedes engine assemblies now. Timing Cover, Valve Covers, Oil Pan on these later Mercedes engines they are all sealed with this special silicone and no gaskets. I have read of other techs needing to re do the job due to leaks because they try to use lower quality silicone products. This one works well as intended. Costs a lot but works. The large tube is enough to do several engines. No leaks on my work so far.

### ⭐⭐⭐⭐⭐ Workde Great
*by T***J on 4 November 2024*

Worked Great way to expensive!

## Frequently Bought Together

- Loctite 212184 5900 Flange Sealant, Heavy Body RTV Silicone, 300 mL Cartridge, Black
- 2-PK Ride Plate Plastic Fitting Replacement for SeaDoo GTX RXP RXT GTI GTS OEM# 293710114

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-08-31*