Spec‑Driven Grease Selection: MIL‑PRF and NATO Standards for AeroShell Products

Continuing our series on AeroShell aircraft greases, we’re talking about the different specifications that they meet (and often exceed). Aircraft operators of all aircraft types follow a long list of specs that fluids and lubricants must meet for use in their fleets, from routine lubrication to specialized applicationsWe provide a quick overview of MIL-PRF, DEF STAN, DCSEA, and NATO codes, which are most commonly used in fleets around the world. AeroShell greases are renowned for their superior protection and improved performance properties, while being readily available and offered at a great price point.

Greenwood Aerospace provides compliant AeroShell products through GSA Advantage for defense and government buyers.

Why GSA Advantage? Because it is the easiest and fastest way for you to procure the parts, accessories, components, and consumables that you need without the hassle of dealing with procurement offices. 

Now, let’s take a look at the greases. 

What Are MIL-PRF and NATO Standards?

All industrial lubricants and consumables are regulated in some way by some regulatory body. For military operations, they are usually MIL-PRF, MIL-G, along with NATO and Joint Service codes. 

MIL-PRF (Military Performance Specifications) are the U.S. military standards that regulate all lubricants, sealants, paints, and other consumables that are used in all aircraft. There are usually multiple manufacturers that provide materials for each MIL-PRF specification, but the spec serves as the guiding tool that tells them what specifications these products must meet. 

NATO codes and Joint Service Designations: simplifying logistics across allied forces and U.S. agencies. After World War II, NATO and the U.S. radically simplified logistics by adopting universal standards for items such as ammunition calibers, munitions, and various aircraft components. Therefore, most AeroShell greases conform to more than one standard, as they are used universally to ease supply chains.  

Greenwood Aerospace's role is to ensure that federal buyers receive the correct AeroShell grease that meets the appropriate military and NATO specifications. Greenwood Aerospace is a U.S. Department of State ITAR-registered company, which enables us to partner with large defense contractors on various military initiatives involving the export of ITAR-controlled items. We hold the following certifications:

UEI: KVSUYYSJS174

DUNS: 604006874

Cage Code: 2Y735

ITAR DDTC Export Compliant

AS9120B QMS Certified

NAICS: 488190, 336413, 332722, 336411, 336413, 481212, 532411

AeroShell Grease 5: High-Temp Wheel Bearing Grease

AeroShell Grease 5 is a high-temperature wheel bearing grease that provides excellent corrosion resistance with minimal water washout and oxidation. 

  • Specs: Meets MIL-G-3545C (obsolete), NATO Code G-359 (obsolete), Joint Service XG-277
  • Performance range: –23°C to +177°C
  • Applications: wheel bearings, engine accessories at high speeds/temps.

This is a grease widely understood as a legacy-grade lubricant for older aircraft, so the U.S. military widely uses it. 

AeroShell Grease 6: General-Purpose Airframe Grease

Used across most brands, including Gulfstream, Embraer, Boeing, and many more, general-purpose airframe greases are a staple item in all maintenance operations. With strong anti-corrosion properties, AeroShell Grease 6 is the standard for most aircraft. 

  • Specs: Approved MIL-PRF-24139A, meets MIL-G-7711A (obsolete), NATO Code G-382, Joint Service XG-271
  • Performance range: –40°C to +121°C
  • Applications: antifriction bearings, gearboxes, plain bearings.

AeroShell Grease 7: Multi-Purpose for Wide Temp Range

Multi-purpose greases are used in various areas throughout the aircraft. It doesn’t necessarily replace other greases used for specialty applications, but it is compatible across a full range of standard maintenance tasks. AeroShell Grease 7 is often used for lubricating highly loaded gears, actuator screws, and even instrument lubrication tasks. 

  • Specs: Approved MIL-PRF-23827C (Type II), COMAC QPL-CMS-OL-302
  • Performance range: –73°C to +149°C
  • Applications: highly loaded gears, actuator screws, airframe lubrication.

AeroShell Grease 14: Helicopter Multi-Purpose Grease

AeroShell Grease 14 is specifically designed for the high-stress environments unique to helicopters. 

  • Specs: Approved MIL-G-25537C, NATO Code G-366, Joint Service XG-284
  • Performance range: –54°C to +93°C
  • Applications: helicopter main and tail rotor bearings, splines.

AeroShell Grease 22: Advanced General-Purpose Grease

AeroShell Grease 22 is a high-performance synthetic grease designed for applications with high bearing loads, high speeds, and a wide operating temperature range. According to the TDS, it is suitable for wheel bearings, engine accessories, control systems, actuators, screw jacks, and more. 

  • Specs: Approved MIL-PRF-81322F (NLGI Grade 2), DEF STAN 91-52, NATO Code G-395, Joint Service XG-293.
  • Performance range: –65°C to +204°C
  • Applications: wheel bearings, actuators, servo mechanisms, motors

AeroShell Grease 33: Universal Airframe Grease

AeroShell Grease 33 is the result of years of research aimed at reducing the number of different greases kept in inventory, as it can perform a wide range of tasks. It is a non-clay-based grease with increased wear and corrosion resistance. 

  • Specs: Approved MIL-PRF-23827C (Type I), Boeing BMS 3-33B, Airbus AIMS 09-06-002, COMAC QPL-CMS-OL-302
  • Performance range: –73°C to +121°C
  • Applications: general airframe lubrication, reduces inventory overlap.

Final Thoughts & Next Steps

AeroShell is a globally recognized leader in aviation-grade lubricants, producing a comprehensive lineup of greases to meet the demands of any fleet. For military and federal aviation flight departments, there is no better partner than Greenwood Aerospace to source your AeroShell greases. With over 40 years in the business, we are trusted professionals in this space, and we trust AeroShell greases with our own fleet of aircraft.  

Take a look at “Matching AeroShell Greases to the Mission”

Call Greenwood Aerospace at 833-GSA-EBUY or email us at gsasales@greenwood.aero for procurement-ready support. These hotlines are specifically for help with GSA Advantage purchases, so don’t hesitate to call today!