Aviation Grease Types: Selection Guide for Aircraft MRO

Aviation grease types are commonly distinguished by their base oil, thickener, and intended application. For aircraft maintenance, the useful question is not simply which grease performs best, but which exact product is specified for the component and service conditions. Wheel bearings, actuators, and specialized systems can call for different formulations that should not be treated as interchangeable.

Key Takeaways

• A grease name or broad category does not establish that it is suitable for a particular aircraft component.
• Base oil and thickener are separate features; both matter when comparing grease formulations.
• Wheel bearings, landing gear mechanisms, and specialized systems may have different lubrication requirements.
• For procurement, identify the exact part number, package requirement, and governing maintenance reference.

What Are the Main Aviation Grease Types?

Grease is generally a lubricating oil held in place by a thickener, with additives that may address needs such as wear or corrosion protection. Buyers often encounter overlapping descriptions: a product can be called a synthetic grease because of its base oil, a lithium-complex grease because of its thickener, and a bearing grease because of its intended use. Those labels describe different aspects of the same material.

This table is a way to read product descriptions, not a substitution chart. Two greases may share an application label while having different base fluids, thickeners, or intended uses.

How Do Grease Types Relate to Aircraft Components?

The component is a better starting point than a generic search for “aircraft grease.” A wheel bearing needs grease that remains effective through its operating conditions and maintenance interval. An actuator or landing gear mechanism may present a different combination of loads, movement, exposure, and access for relubrication. The specified grease reflects those considerations for the particular assembly.

For example, AeroShell Grease 22, part number ASG22, is listed for wheel bearings, actuators, and landing gear and is identified in its product description as approved to MIL-PRF-81322 and NATO G-395. That information is useful when identifying a candidate product, but the component and maintenance task still determine what a buyer should order.

Mobil Aviation Grease SHC 100 provides a different comparison point. Its listing identifies a PAO synthetic base fluid and lithium-complex thickener, and describes resistance to water wash, wear, rust, and corrosion. A separate listing describes its use in aircraft wheel bearings. Similar component use, however, does not make it an automatic replacement for another wheel-bearing grease.

Other products illustrate why an application word alone is insufficient. Armite VV-P-236 Light Grade Lubricating Grease is described for light to moderate lubrication. A product described as a high-temperature bearing grease may instead be marketed around industrial equipment. “Bearing grease” tells a buyer what to investigate; it does not identify every bearing in which that grease belongs.

How Should Buyers Compare Base Oils and Thickeners?

Start by separating formulation terms from performance claims. The base oil supplies lubrication, while the thickener gives grease its structure. Additives and the finished formulation also affect how a product behaves. A synthetic base oil is therefore not, by itself, a complete specification for the grease.

• Base oil: Record the stated type when available, such as PAO or silicone, rather than grouping all synthetic products together.
• Thickener: Note whether the listing identifies a system such as lithium complex or lithium soap. The two terms should not be collapsed into one product identity.
• Application: Distinguish a documented use for a specific product from a general statement about a family of greases.
• Environmental demands: Check the task’s temperature, water-exposure, and corrosion considerations against the specified product information.
• Packaging: Confirm the required container size or dispensing format, particularly when maintenance instructions or shop procedures call for one.

For a concrete chemistry comparison, Mobil Aviation Grease SHC 100 is listed as PAO-based with a lithium-complex thickener, while Molykote 44 is described as using silicone technology with a lithium-soap thickener. Both may be described using the broad word “grease,” but their formulation descriptions are different. That distinction helps prevent a purchasing request from being reduced to an imprecise phrase such as “synthetic bearing grease.”

What Should an MRO Purchase Request Include?

A clear request lets a supplier identify the requested item without guessing at an equivalent. The part number is the anchor; the component and documentation references explain the context. Where the buyer needs supporting paperwork or a particular package, those requirements should be stated rather than assumed.

1. Provide the manufacturer or brand and exact product designation or part number.
2. Specify the required package size and quantity, if known.
3. Identify the aircraft or component application and the maintenance-document reference used to select the material.
4. State any required documentation or batch-identification details in the request.
5. Ask the supplier to identify any proposed alternative explicitly rather than silently substituting one.

For example, a buyer might write: “Please quote AeroShell Grease 22, PN ASG22, in the package size and quantity shown on our attached requisition. Identify the product offered and provide the documentation specified in the requisition. Do not substitute another grease without review.” This wording identifies the requested material while leaving any technical decision about an alternative with the appropriate maintenance team.

Caution: A catalog description, shared grease category, or cited product approval does not by itself establish airworthiness or authorize use on a specific aircraft. Confirm applicable approvals and any substitution through the aircraft maintenance documentation and follow the grease manufacturer’s current data sheet and instructions.

Sourcing from CraftJetAero

CraftJetAero lists aviation chemicals and lubricants, including the grease products discussed above. Buyers can request a quote from CraftJetAero by part number and include package, quantity, and documentation requirements so the requested item is unambiguous.

Frequently Asked Questions

What are the main ways to classify aviation grease types?

Greases can be classified by base oil, thickener, grade, or intended application. Because these categories overlap, an exact product designation is more useful for purchasing than a broad type name alone.

Is synthetic aviation grease the same as lithium grease?

No. “Synthetic” describes the base oil, while “lithium” describes a thickener family. A grease can be both synthetic and lithium-thickened, as illustrated by the PAO and lithium-complex formulation listed for Mobil Aviation Grease SHC 100.

Can any aviation bearing grease be used in an aircraft wheel bearing?

No. “Bearing grease” is a broad description, and products marketed for bearings can have different formulations and intended uses. Identify the grease specified for the particular wheel assembly and maintenance task.

Does a product specification approval authorize its use everywhere on an aircraft?

No. A product approval identifies a stated qualification, not every installation in which the product may be used. The applicable maintenance instructions determine the material required for a particular task.

What information should I send when requesting an aviation grease quote?

Send the exact brand and part number, required quantity and package size, and any documentation requirements. Include the application or maintenance reference when it helps distinguish the requested item from a similarly named product.