Understanding Military Specifications and Standards for Aviation and Aerospace Sealants

MILSPECS Create Standardization in the Industry

What are MILSPECS?

Within the United States military, standardization is key for efficient maintenance, repair, and operability. To achieve that, the U.S. Department of Defense (DoD) has created defense specifications and standards, collectively referred to as “milspecs,” informally, and abbreviated "MIL-STD" and "MIL-SPEC." These are a major part of the DOD’s Standardization Program, which, “seeks to limit variety in purchased items by stipulating certain design details.”[1]

According to the U.S. Government Accountability Office (GAO), military specifications "describe the physical and or operational characteristics of a product," while military standards "detail the processes and materials to be used to make the product." For example, a specification might describe the kind of wire to be used in an electrical circuit and a standard might describe how the wire is to be fastened in a circuit and what tests should be conducted on the circuit.

More plainly, a military standard part, also referred to as a MIL-STD or MIL-SPEC part, is a component that meets standard requirements established by the U.S. DoD in order to meet their objective of standardization.

[1] https://www.gao.gov/assets/nsiad-95-14.pdf

What is the purpose of MILSPECS For Aerospace and Aviation Sealants?

Milspecs serve several purposes. First, they offer standardization, which meets multiple defense-related objectives. Second, standardization ensures interoperability between products. Buyers can rest assured that if they buy the same sealant from two different companies and each product meets the same milspec, they can be used interchangeably. Third, milspecs provide a layer of protection against contractor fraud. If it is certified to meet the standard, fraud is less likely. Fourth, milspecs promote greater opportunities for competition among contractors by laying out exact standards to meet in product creation.

What MILSPECS Are Common in Sealants?

Here are some examples of MILSPECS in aviation sealants sold by NSL Aerospace.

MIL-S-8802

Sealing compound, temperature-resistant, integral fuel tanks and fuel cell cavities, high-adhesion (superseded by SAE AMS-S-8802). Example product meeting this military specification: CS3204 Class A & B

MIL-S-83430

Sealing compound, integral fuel tanks, and fuel cell cavities, intermittent use to 360 degrees F (182 degrees C) (superseded by AMS-3276). Example product meeting this military specification: CS5500 Class A & B

MIL-S-81733

Sealing and coating compound, corrosion inhibitive (superseded by MIL-PRF-81733D). Example product meeting this military specification: CS3213 Class A, B & C

MIL-S-38228

Sealing compound, environmental, fir aircraft surfaces. Example product meeting this military specification: CS2415 Class B

MIL-S-11031

Sealing compound, adhesive; curing (polysulfide base). Example product meeting this military specification: CS3202 Class B

MIL-PRF-8516G

Sealing compound, synthetic rubber, electric connectors and electric systems, chemically cured. Example product meeting this military specification: CS3100 Class 1, 2 & 3