Anti-seize lubricant is a metal-filled paste applied to threaded fasteners and mating surfaces to prevent galling, seizure, corrosion, and heat welding so parts come apart later.
A steel bolt threaded into an aluminum head can bond to the softer metal and snap off on removal. Anti-seize lubricant — a heavy paste loaded with copper, graphite, or aluminum particles — sits on the threads, lowers friction during assembly, and keeps corrosion and high heat from fusing the parts. It does two jobs at once: it helps a fastener go together smoothly and ensures it comes apart years later. Here is what it does, where it goes, and the mistakes that cause real damage.
Where Anti-Seize Lubricant Actually Gets Used
Anti-seize earns its place on any metal-to-metal joint facing heat, moisture, or long service life — especially where two different metals meet.
Permatex Anti-Seize Lubricant (80208) lists spark-plug threads in aluminum heads, exhaust-manifold and engine bolts, brake anchor pins, U-bolts, spring bolts, hinges, gears, chains, sprockets, and industrial turbine hardware.
Permatex Copper Anti-Seize Lubricant (09128) targets stainless steel and similar alloys: oxygen sensors, knock sensors, thermostat-housing bolts, fuel-filter fittings, pump and valve hardware, and battery-cable connections — which explains why a mechanic’s shelf holds two or three cans.
LOCTITE LB 8008 C5-A, a copper-and-graphite paste from Henkel, is rated to 1,796°F and called out for screws, nuts, pipes, exhaust bolts, and brake-caliper bolts. Henkel lists compatibility with copper, brass, cast iron, steel, stainless-steel alloys, plastics, and nonmetallic gasket materials.
| Product | Stated Temperature Range | Best Suited For |
|---|---|---|
| Permatex Anti-Seize 80208 | -60°F to 1,600°F | Spark-plug threads, exhaust bolts, brake anchor pins, hinges |
| Permatex Copper 09128 | -30°F to 1,800°F | Stainless steel, O2 and knock sensors, battery-cable connections |
| LOCTITE LB 8008 C5-A | -20°F to 1,796°F | Exhaust bolts, brake-caliper bolts, pipes, threaded nuts |
How To Apply It Correctly
Apply a thin, even coat to clean, dry threads and the flats of the nut or bolt — a heavy smear is wrong. Permatex recommends cleaning mating surfaces first (brake and parts cleaner where appropriate), wire-brushing loose surface rust, applying anti-seize, reassembling at normal torque values, and wiping off excess. Clean the aerosol brush afterward.
Henkel’s guidance for LB 8008 matches: a clean, grease-free mating surface and a thin coating on threads and nut and bolt flats before assembly. Excess paste migrates into nearby components and makes cleanup harder.
The Torque and Compatibility Mistakes That Bite
The biggest error is torquing an anti-seized bolt to its dry specification. Henkel states that a lubricated bolt can produce greater clamp load at the same torque, so the fastener can be overstressed even though the wrench read the “correct” number. Use the maker’s lubricated-thread specification when one exists.
More hard rules:
- Skip wheel studs and lug nuts. Permatex warns its standard and copper anti-seize products are not for wheel-lug-nut or wheel-stud applications.
- Don’t use it as a threadlocker. It prevents seizure and eases disassembly, not holding power.
- Match the formulation to the environment. Copper and graphite versions may be wrong where electrical, galvanic, chemical, or oxygen-system compatibility matters.
- Avoid pure-oxygen systems. Permatex warns against oxygen-rich systems and chlorine or other strong oxidizing materials.
- Store it cool and dry. Permatex recommends 46°F to 82°F for unopened containers; Henkel lists 46°F to 70°F as optimal for LB 8008.
Read the Safety Data Sheet before handling these pastes and check compatibility for your exact metals, seals, and process chemicals. For side-by-side formulation comparisons, see this roundup of the best anti-seize lubricants for stubborn fasteners.
Permatex’s technical data sheet is the most reliable place to confirm a product’s stated limits. Permatex Anti-Seize technical data sheet
Common Questions
Does anti-seize make a bolt come loose?
No — loosening is not the typical failure. Anti-seize reduces friction, so the same torque produces more clamp load, and excess preload is the real risk. Follow the maker’s lubricated-thread torque spec, and use a threadlocker when the job calls for holding power.
Can I use anti-seize on spark plugs?
Yes, on the threads of a plug going into an aluminum head — one of the uses Permatex lists for 80208. Apply a thin coat only, keep it off the electrode and insulator, and follow the plug maker’s installation torque. Many plug manufacturers now ship coated threads, so check first.
What is the difference between copper and regular anti-seize?
Standard anti-seize covers general hardware like spark plugs, brake pins, and hinges up to 1,600°F.
Sources
- Permatex. “Anti-Seize Lubricant Technical Data Sheet (80208)” Supplies the application list, service range, and step-by-step instructions.
- Henkel. “LOCTITE LB 8008 C5-A Technical Data Sheet” Supports the material compatibility list and storage range.
- Henkel. “LOCTITE LB 8008 C5-A Product Page” Source for the 1,796°F temperature resistance claim.