LOCTITE 518 Automotive Anaerobic Gasket Maker & Flange Sealant - Sensor-Safe, Low Odor, Non-Corrosive - 50 ml, 1 Pack

Overview

Loctite 518 is a single-component anaerobic gasket maker designed for close-fitting metal flanges. Supplied in a 50 ml tube (1 pack), it cures when the joint is sealed from air, creating a form-in-place gasket suitable for low-pressure transmission and engine joints. Its thixotropic formula minimizes migration and squeeze-out, helping to keep flanges clean and aligned during assembly.

The product supports both active metals such as mild steel and passive substrates like aluminum with low copper content. It tolerates gaps up to 0.25 mm (0.01 in) and minor surface contamination from cutting oils, lubricants, anti-corrosion agents, and cleaners containing surfactants and inhibitors. This flexibility makes it practical for real-world workshop and field tasks where surface prep isn’t perfect.

Key benefits

• Designed primarily for aluminum, iron and steel flanges, delivering a consistent seal across common automotive joints
• Ideal for on-the-spot repairs or when a conventional gasket is unavailable
• Suitable for transmission case coverings and engine casings
• Thixotropic formula minimizes liquid migration, reducing clean-up and potential mess
• Sensor-safe and low-odor formulation suitable for enclosed spaces
• Non-corrosive to typical automotive metals, preserving surfaces during service

What LOCTITE 518 can do for you

• Seals close-fitting joints between gearboxes and engine casings as a form-in-place gasket, reducing the need for pre-cut gaskets
• Provides robust curing right after assembly so you can move to the next step with confidence
• Tolerates minor contamination from common oils and cleaners, maintaining performance in mixed workshop environments
• Offers automotive aftermarket value by supporting emergency repairs and ongoing maintenance across makes and models

Application tips

• Prepare mating surfaces by cleaning and drying; avoid residual oil or coolant on the contact area
• Apply a consistent bead along one flange face, then bring the surfaces together and clamp as needed
• Ensure a close-fit joint; cure occurs in the absence of air; avoid introducing air pockets

In practice, LOCTITE 518 can be a practical choice for fleet maintenance crews, hobbyists, and professional technicians who want a reliable, sensor-safe seal for gaskets in tight spaces. While it is not a guaranteed fix for every scenario, it offers a predictable pathway to form a gasket in situations where conventional gaskets are not available.

Packaging and storage

Comes in a 50 ml tube, 1 pack. Store in a cool, dry place away from heat sources to preserve sealant performance and reliability across automotive applications.