How Does an Anti Seize Compound Work?

An anti seize compound is a type of lubricant that prevents seizing, corrosion, and galling as metal parts rub against each other. Mainly used in the automotive, marine, and aeronautics industries, it is applied to parts like bolts, screws, and valves to ensure smooth operation and easy removal. This article explores the working and types of an anti seize compound.

Table of contents

• What is an anti seize compound?
• Reasons to use an anti seize compound
• Working principle
• Which anti seize compound to use?
• Applying an anti seize mixture
• How to remove anti seize compound?
• Anti seize compound substitute
• Applications
• FAQs

What is an anti seize compound?

An anti seize mixture is a particular type of lubricant made to stop metal parts from sticking, damaging each other, and rusting. It's made from a mix of lubricating solids like graphite, copper, aluminum, and zinc, all held together in a base of grease or oil. Mechanical elements like bolts, studs, tubing, pulleys, fittings, and chains use anti seize compounds to prevent damage.

Reasons to use an anti seize compound

There are several reasons to use an anti-seize compound:

• Prevents seizing and galling: Seizing occurs when the two surfaces become so tightly bound together that they cannot be separated, while galling occurs when the two surfaces become so worn that they lose their ability to function properly. Anti seize compounds provide a lubricating film between two metals, which helps to reduce friction and prevent them from seizing together. This is especially important for high-temperature applications, where the metals are more likely to expand and contract, which can increase the risk of seizing.
• Reduces corrosion: Anti seize compounds can also help to protect metals from corrosion. This is because they create a barrier that prevents moisture and other contaminants from reaching the metal surfaces.
• Ease of disassembly: Anti seize compounds can make it easier to disassemble threaded fasteners, even after exposure to high temperatures or corrosive environments. This is because the lubricant reduces friction and prevents the metals from seizing together.
• High temperature resistance: Some anti-seize compounds are designed for use in high-temperature applications, such as exhaust manifolds and engine components. These compounds can withstand temperatures of up to 1090 𐩑C (2000 𐩑F)

Read our tribosystems article for more details on wear and friction in mechanics.

Working principle

The lubricating solids in the anti seize mixture fill in the tiny holes and gaps on the metal parts' surface, stopping them from interacting with oxygen, water, or other corrosive elements. This helps to make a smooth surface and stops the parts from weakening. The grease or oil base of the anti seize mixture also provides extra lubrication, helping the parts to move easily and freely. In short, anti seize mixtures work by putting a barrier between the metal parts, which reduces the rubbing and stops them from rusting or sticking.

Anti seize compounds vs normal lubricants

Anti seize compounds differ from normal lubricants in several ways:

• Solid lubricants: Anti-seize compounds contain a high concentration of solid lubricants, while normal lubricants typically only contain a small amount of solid lubricants or none at all.
• Extreme pressure (EP) additives: Anti-seize compounds often contain EP additives, which help to protect metal surfaces under high pressure conditions. Normal lubricants may or may not contain EP additives.
• Temperature resistance: Anti-seize compounds are typically designed to withstand high temperatures, while normal lubricants may not withstand such extreme conditions.

Read our lubrication article for more details on general lubrication process.

Which anti seize compound to use?

There are two stages of lubrication in an anti seize compound:

1. High quality grease that adds as a base lubricant and can work up to 200 𐩑C (392 𐩑F).
2. The solid lubricants in the grease work up to 1200 𐩑C (2192 𐩑F).

Selecting an anti seize compound requires carefully analyzing some parameters.

• Environment and application: In damp settings, choose an anti seize mixture of marine quality. This is often used for assembling engines, oiling bolts, lubricating sliding door tracks, heat exchanger bolts, and boiler covers. Use anti seize compounds with non toxic non metallic components if the intended use is in the food industry.
• Temperature: Consider the temperature conditions and how much heat or cold the mixture needs to resist. Mixtures based on copper and aluminum are suitable for high temperatures; marine grade is good for cold temperatures, and nickel works well for both.

Table 1 summarizes the main solid lubricants used in anti seize compounds.

Table 1: Lubricating solids in anti seize compounds

Lubricating solid	Benefits	Limitations	Applications
Copper	Works up to 800 - 1200 𐩑C (1472 - 2192 𐩑F) and offers good corrosion resistance for all steel	Copper on stainless steel can crack and break stainless steel parts	Perfect for high heat applications
Aluminum	Works up to 800 - 1200 𐩑C (1472 - 2192 𐩑F) and good for use on stainless steel	When aluminum touches an electrolyte; it turns into a tiny anode compared to the large cathode of the steel. Usually, it breaks down fast and doesn't protect the steel surface. Not recommended to be used on carbon steel.	Suitable for low heat applications
Nickel	Works up to 1400 𐩑C (2552 𐩑F), has good corrosion protection and anti seize properties, and works well on steel and stainless steel	Nickel is carcinogenic	Marine and offshore applications
Graphite	An excellent conductor of electricity and can work as a solid lubricant at high temperatures (up to 450 𐩑C or 842 𐩑F).	Corrosive in the marine environment, also speeds up the corrosion of ferrous alloys	Food processing, and oil and gas equipment

Applying an anti seize mixture

Before using an anti seize mixture, clean the parts with a solvent that removes grease. Use the degreaser to remove oil, grime, and other bits, then let it dry. With a small brush, put the anti seize mixture on the male part's threads, and ensure it gets into the gaps. The mixture should be spread over the whole part, including any non-threaded parts, if they are also a part of the assembly. Also, put a slim layer of the mixture under the bolt's head, the nut's surface, and all parts of the washer.

How to remove anti seize compound?

While it's not necessary to apply more anti seize mixture for ongoing use, there may be times when it's desirable to remove it entirely. Just as with cleaning and preparation before applying anti seize mixtures, a grease-removing solvent should be used for its removal. Regardless of the type of anti seize mixture chosen, a solvent degreaser proves effective. Apply the degreaser with a cloth and then wipe it off. Ensuring that parts are clean and free of grease when not in use is crucial to maximizing the utility of the materials.

Anti seize compound substitute

A good substitute for an anti seize compound depends on the specific application. However, some common substitutes include:

• Grease: Grease is a general-purpose lubricant that can prevent galling and seizing in many applications. However, grease is less effective than anti seize compounds at preventing corrosion.
• Graphite: Graphite is a solid lubricant that can prevent galling and seizing in high-temperature applications. However, it is less effective than an anti seize compound at preventing corrosion or the fastener from loosening.
• Molybdenum disulfide: Molybdenum disulfide is a solid lubricant similar to graphite. However, it is more effective at preventing corrosion and the fastener from loosening.
• Nickel grease: Nickel grease is a specialized lubricant designed to prevent galling and seizing in high-temperature and high-pressure applications. It is also effective at preventing corrosion.
• Copper grease: Copper grease is a specialized lubricant designed to prevent galling and seizing in marine applications. It is also effective at preventing corrosion.

Read our lubricant testing article for the common test methods and standards for lubricants.

Applications

Anti seize mixtures are made for use and to meet the standards for use in specific applications, including the following:

1. Aerospace: Aerospace mixtures are suitable for aerospace uses and will meet military specifications and standards.
2. Automobile: Automotive mixtures are used for various threaded fasteners and things like brake calipers, spark plugs, and engine parts. These are picked based on their compatibility with the material and temperature.
3. Food grade: Food grade anti seize mixtures include those that have approval from the National Sanitary Foundation (NSF) or are otherwise made and suitable for use in equipment that processes food, drinks, or medicine and where these things might come into contact with the anti seize compound. Food-grade anti seize compound is used in chain sprockets, manifold tubes, and pump gaskets.
4. Marine: Marine mixtures are suitable for use on ships, dockyards, or boats and resist oxidation.
5. Military: Military-grade mixtures meet MIL-STD or MIL-SPEC standards and are suitable for military applications.

FAQs

What is an anti seize lubricant used for?

An anti seize lubricant prevents seizing, corrosion, and galling between metal surfaces, especially in high-temperature and high-pressure environments.

Which is a high temperature anti seize compound?

Copper is a high temperature anti seize compound.