Loctite Copper Anti-Seize Lubricant Brush-Top Jar — 8 oz, High-Temp Protection & Conductive Paste

Loctite 38650 Copper Anti-Seize Lubricant (8 oz, brush top) is a high-temperature copper paste formulated to prevent seizing, corrosion and galling on threaded and metal mating surfaces.

This brush-top jar contains a copper-filled anti-seize compound designed for demanding automotive and industrial service where heat, pressure and dissimilar metals can cause threads and fittings to lock up. The formula stays stable over a wide thermal range and helps maintain serviceability of fasteners, sensors and fittings while also providing electrical conductivity where needed.

Where is Loctite 38650 most useful?

The paste is intended for threaded connections and metal-to-metal contact points exposed to elevated temperatures and corrosive conditions. It's commonly used on exhaust components, engine bolts, sensors and battery terminals to ease future disassembly and reduce damage from galling.

• Spark plug threads in aluminum engines
• Exhaust manifold and header bolts
• Oxygen and knock sensor threads
• Thermostat housings, fuel fittings, battery cable connections

How does the copper anti-seize perform under heat and harsh environments?

Loctite 38650 is formulated to remain effective across a broad temperature span, resisting breakdown, oxidation and washout under typical automotive and industrial heat loads. Its copper fillers help maintain conductivity and mechanical separation even at high temperatures, which protects threads from fusing or corroding together.

• Temperature tolerance from about -30°F up to 1800°F (-34°C to 982°C)
• Copper particles support electrical continuity where required
• Resists corrosion and reduces galling between dissimilar metals

How do I apply the brush-top anti-seize correctly?

The jar’s built-in brush applicator makes it straightforward to coat threads and contact surfaces evenly. Apply a thin, even layer to clean mating surfaces; avoid over-application to prevent excess compound from migrating into unwanted areas.

• Clean threads and seating surfaces of oil, dirt and old sealant first
• Brush a light, continuous coat onto male threads or contact areas
• Wipe away excess and torque per manufacturer specifications

Will using this anti-seize affect torque readings or sensor function?

A properly applied, light coating can slightly change friction and therefore torque readings; adjust torque practices accordingly and follow component manufacturer guidance. For sensors, use only as recommended — the copper content provides conductivity but do not allow paste to contaminate sensing elements.

• Apply sparingly on torque-critical fasteners and follow torque charts
• Keep compound off sensor faces; limit to threads only when specified
• Re-torque procedures may differ if anti-seize is used—consult specs

Who is this for? Mechanics, fleet technicians, heavy equipment operators and DIY enthusiasts who need a durable, high-temperature anti-seize for engines, exhaust systems and electrical grounding points will benefit from Loctite 38650. Choose this 8 oz brush-top jar when you want easy application, long thermal stability and copper-enhanced conductivity to simplify maintenance and protect metal fasteners from seizing, corrosion and galling.