In the military and defense sector, reliable and durable equipment is a necessity for the success of missions and the safety of personnel.
Mil Spec fasteners, otherwise known as military specification hardware or military fasteners, serve a number of purposes in systems and devices.
From use in unmanned drones to aircraft structures, they proof seals and/or produce strong joints to ensure sensitive equipment maintains its integrity, no matter how challenging the environment is.
The difference between commercial fasteners and military standard fasteners
Mil spec fasteners do look a lot like their commercial fastener cousins. However, they have been made to strict military specifications and come from materials from DFAR countries.
These specifications cover many different areas, including plating, material qualities, drive type, threads, hardness, tensile strength, and dimensions.
Military fasteners distributors will have manufacturer’s certification and will meet all of the government requirements in place.

Different types of Mil Spec Fasteners
Some of the main category list of mil-spec fasteners include:
- Mil-spec electronics
- Mil-spec rivets
- Mil-spec pins
- Mil-spec nuts
- Mil-spec washers
- Mil-spec bolts
- Mil-spec screws
- Mil-spec cap screws
Applications of Mil Spec Fasteners
Mil-spec fasteners are used in a number of military systems, equipment, custom engineered applications, and devices, including:
- Unmanned drones
- Submarines
- Ships
- Missile systems
- Machinery
- Land-vehicles
- Aircraft
Defense contractors painstakingly design, construct, and test these fasteners to ensure they meet stringent military specifications. After all, failure of this part could result in catastrophic consequences.
Properties of mil-spec fasteners
When it comes to military fasteners, the DFARS requirements are exceptionally high to make sure the equipment operates as intended throughout its complete service life.
The military grade standard requires hardware to be constructed to tolerances using a number of high-performance materials and precision techniques.
Some of the common materials used include steel, stainless steel, copper, brass, and aluminum. The selection depends on the needs of the application in question.
Properties that are essential include the following:
- Durability – Reliability and durability are essential when purchasing military fasteners. They need to be designed and manufactured for a long working life under operating conditions that are hugely demanding.
- Pressure resistance – Pressure resistance is a must for a lot of ballistics, naval, and aerospace applications. Pressure can be low, high, or fluctuating.
- Temperature resistance – This characteristic means that the mil-spec fastener can withstand exposure to fluctuating, high, or low temperatures. In naval and aerospace applications, fasten materials can be exposed to extremely low temperatures deep in the water or high in the atmosphere, for example.
- Corrosion resistance – Corrosion resistant steel and other materials like this are often used to ensure that the mil-spec fastener keeps its integrity whenever it is exposed to corrosive compounds and/or exposed to the elements.
Full traceability is essential
When ordering machine screws or mil-spec fasteners, full material traceability is paramount. This means you are able to see every element of the manufacturing process, from raw materials to the finished product.
Traceability data must be recorded in the same way inspection results are, verifying traceability needs and making sure final products deliver exceptional consumer satisfaction.
The ability to trace ensures product quality, enhances operational efficiency, and prevents product recall.
Contact Metric Bolt for premium mil-spec fasteners
Here at Metric Bolt, we understand the responsibilities and complexities of being a DFARS compliant supplier for the military.
You can be sure that we will exceed your expectations. All of our military fasteners and parts are certified and fully traceable for your complete peace of mind.
If you have any questions about our mil-spec fasteners or the steps we take to meet stringent military specifications, please do not hesitate to contact our friendly team at Metric Bolt today.