1. Anti-seize pastes are especially suited for severe-duty applications involving high loads,
harsh environments, extreme heat, or low sliding speeds or oscillatory movements.
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Anti-Seize Pastes Deliver Solid Lubricants
Anti-seize pastes are a class of specialty lubricants that contain synergistic
combinations of lubricating solids in base oils. High solids content makes
these pastes far different than conventional greases, which are formulated with
little or no solid lubricants. They are especially suited for severe-duty
applications involving high loads, harsh environments, extreme heat, or low
sliding speeds or oscillatory movements.
Typical grease is essentially a lubricating fluid, containing 65 to 95% base oil, 5
to 35% thickeners and up to about 10% special-purpose additives, including
some solids. In contrast, a paste will usually have only 40 to 60% base oil that
is thickened into a greaselike consistency with 40 to 60% solid lubricants.
Pastes are a convenient form for easy application of solid lubricants, which are
needed in challenging conditions. Even if the carrier oil is squeezed out under
load or driven off by high temperatures, the solids maintain a strong lubricating
film.
Paste ingredients go beyond greases
In a typical anti-seize paste, different solid lubricants are used alone or in
combinations as the surface-active materials needed for effective boundary
lubrication in a tribological system. Different base oils are used as wetting
agents and carrier fluids for the solids. Some of the formulation choices are:
• Solid lubricants: Molybdenum disulfide (MoS2); graphite; polytetrafluoroethylene (PTFE); calcium
hydroxide; metal phosphates; inorganic oxides; and various metals, like copper, tin, lead, zinc,
aluminum and nickel.
• Base oils: Mineral oils or synthetic oils, including polyalphaolefins (PAO), polyalkylene glycols (PAG),
diesters (DE), polyolesters (POE), silicones and perfluoropolyethers (PFPE).
Types of anti-seize pastes
Different ways are used to classify paste types, including color (black pastes, white
pastes), composition (MoS2, metal, metal-free), specialty form (grease pastes, oil
pastes), or application (assembly pastes, thread pastes). Several types of pastes
are summarized here.
• Black pastes are mainly composed of MoS2 and graphite. They are used as
assembly pastes to help prevent galling and cold welding and to aid in future
disassembly.
• White pastes, also used as assembly pastes, have metal phosphates and hydroxides as solid
lubricants and are particularly good at helping to prevent fretting corrosion caused by micro-vibrations
of machine components.
• Metal pastes are often used as anti-seize pastes on threaded connections and can contain various
metal powders with other solid lubricants. They help ensure proper tightening torque.
• Grease pastes typically provide thick-film, long-term lubrication with about 25% solid lubricants in oil
with small amounts of thickeners for added consistency.
• Oil pastes have a reduced amount of solid lubricants – 10 to 20%, for example – with the balance
predominantly oil. These oil pastes are often good for long-term lubrication and can provide