Fasteners play a vital role in making several objects, which is why they’re used in many different industries. In this post, we’re going to explore the use of fasteners in custom military applications and the aerospace industry.
What is a fastener?
There’s only one place to begin, and this is by explaining what a fastener is. A ‘fastener’ is an encompassing term that describes any type of hardware drive that mechanically affixes or joins two or several objects together.
Some examples of fasteners include:
Understanding the difference between commercial fasteners and mil-spec fastening hardware
Military grade fasteners play a vital role across numerous industries, including aerospace, navy, and army.
The bolts and nuts used in the military industry are very much similar to a standard fastener. Nevertheless, there are some key differences that demand an in-depth knowledge and skill of application to adhere to the stringent standards and regulations laid out by government bodies and defense contractors.
Every military fastener, whether it’s a bolt, screw, or nut, must be constructed to strict standards that thoroughly define the fasteners attributes, such as:
- Plating
- Material qualities
- Drive type
- Threads
- Hardness
- Tensile strength
- Dimensions
This isn’t an exhaustive list either. Furthermore, there needs to be careful control when it comes to the supply and production of all military equipment along the entire supply chain. And yes, this even applies to tiny fastening hardware, which means extreme care needs to be taken to ensure the military supply chain is secure.
Suppliers must adhere to the government’s standards in terms of security, production quality, and from DFARs compliant countries.
It’s also worth noting that a mil-spec fastener will come with a complete record so that every part of it can be traced back to the source.
Standards for military-grade fasteners
The development of several United States Military Standards and specifications came about due to World War II. This is because American nuts, bolts, and screws were historically not fully interchangeable with their British counterparts, meaning they wouldn’t fit British equipment correctly.
The United States Military Standards were, therefore, compiled to provide specifications for any piece of equipment used for defense or military purposes, including fasteners.
One of the main components of most military standards is material traceability. In simple terms, hardware manufacturers need to be able to effectively trace their materials to their source. Furthermore, when parts go into the supply chain, they must provide traceability for this too, typically through bar codes or similar methods.
This traceability is designed to help make sure the correct parts are utilized and quality standards are adhered to at every step in the manufacturing process. Furthermore, if a part is not up to standard, it can be traced back to the source.
Some of the quality credentials fastener manufacturers need to adhere to
When choosing a manufacturer for military fasteners, you need to ensure they adhere to the relevant government and military standards. Examples include the following:
- MIL-S-1222 H
- MIL-DTL-1222 J
- AS9100D
- MIL-STD-45662A
- ANSI NCSL-Z540.3
- MIL-I-45208A
- EB2678L
- ISO 9001
- Navy Level 1
Who uses military-spec nuts, bolts, and screws?
Military-grade fasteners can be utilized by anyone servicing or manufacturing military equipment.
To decipher whether a product must be manufactured with mil-spec parts there tends to be a bill of materials (BOM), which calls for certain mil spec fastener in relation to a part number.
Military-grade screws, nuts, bolts, wedge anchors, and other fasteners are typically used in naval and aerospace vessels, where the imperativeness of quality control cannot be understated. However, there are plenty of other instances that call for mil-spec parts.
Highlighting the key feature differences between a commercial and mil-spec fastener
Mil-spec parts are tested and manufactured to stringent military standards to ensure reliability and performance. Generally speaking, commercial fasteners don’t have the same quality standards.
Some of the key differences between a commercial and a mil-spec fastener are as follows:
- Military-grade spec is designed to lower non-uniform stress, as the bolt is torqued, therefore, lowering premature fatigue
- Threads are pressed into the steel, not cut, therefore, ensuring strength throughout the complete shank
- Often bolts will be plated with cadmium for improved corrosion resistance in comparison to commercial-grade zinc-plated bolts
- Physical certification, chemical certification, manufacturer’s certification, and full lot material traceability are features of mil-spec styles
Understanding fasteners and their use in the military and aerospace sectors
So there you have it: an insight into the use of fasteners in military and aerospace applications. Rather than simply looking for parts at great prices, military and aerospace organizations are concerned with securing hardware that adheres to the very strict standards that are in place.
