Why Aircraft-Grade Fasteners Are the Unsung Heroes of Aviation Safety

When we think about aviation safety, our minds typically go to avionics, engines, and structural airframes. Rarely do we think about the thousands of bolts, nuts, screws, and rivets that quite literally hold an aircraft together. Yet, these small components are among the most critically inspected, rigorously certified, and precisely engineered parts in the aerospace supply chain.

This post breaks down why sourcing the right aircraft-grade fasteners matters — and what procurement teams, MRO operators, and aerospace engineers need to know before placing their next order.

What Makes a Fastener “Aircraft-Grade”?

Not all fasteners are created equal. A standard hardware store bolt may look identical to an aircraft bolt, but the differences lie in material composition, heat treatment, tolerances, and traceability documentation.

Aircraft-grade fasteners typically meet standards set by:

• AN (Army-Navy) — the oldest U.S. military standard for hardware
• MS (Military Standard) — covers a wide range of aerospace fastener specifications
• NAS (National Aerospace Standard) — high-strength, precision hardware for structural applications
• AS (Aerospace Standard) — maintained by SAE International for modern aerospace use

These standards mandate strict material properties (typically alloy steel, titanium, or corrosion-resistant steel), dimensional tolerances, surface treatments, and minimum tensile/shear strength ratings.

The Role of Traceability in Aerospace Hardware

One of the biggest differentiators between standard industrial fasteners and aerospace-grade components is full material traceability. Every aircraft fastener used in a certified repair or manufacturing operation must be accompanied by documentation that traces the part back to its original manufacturer — including mill certifications, heat lot numbers, and certificates of conformance (CoCs).

This is why sourcing from an AS9120B and ISO 9001:2015 certified distributor is non-negotiable for aviation procurement. These certifications confirm that a distributor has quality management systems in place to verify part authenticity, inspect incoming stock, and maintain records throughout the supply chain.

Counterfeit fasteners are a real and documented threat in aviation. The FAA and various regulatory bodies have cataloged incidents where substandard or fraudulently marked hardware entered the supply chain — with potentially catastrophic consequences.

Fasteners Distribution holds AS9120B, ISO 9001:2015, and FAA AC 00–56B accreditations — ensuring every part sold meets the traceability and quality standards required by aviation operators.

Common Types of Aircraft Fasteners and Their Applications

1. Bolts

Aircraft bolts are used in primary structural joints where high tensile loads are expected. Common types include:

• AN3–AN20 hex-head bolts — general-purpose airframe bolts
• Shear bolts — designed to resist lateral (shear) loads, not tensile loads
• Close-tolerance bolts — used where precise fit is critical to structural integrity

2. Nuts

Aircraft nuts are almost always self-locking to prevent loosening due to vibration — a major concern in aerospace environments. Types include:

• AN365 (self-locking elastic stop nuts)
• MS21042 (lightweight self-locking nuts)
• Castle nuts with cotter pins — used for safety-wire applications

3. Screws

Machine screws, structural screws, and drive screws each serve different functions across aircraft panels, access doors, and interior fixtures. Selection depends on shear strength requirements and accessibility for maintenance.

4. Rivets

Rivets are the backbone of aircraft skin assembly. Solid rivets (AN426, AN470) are driven by hand or pneumatic tools, while blind rivets (like Huck bolts) are used where only one side of the joint is accessible.

5. Washers and Pins

Washers distribute load, prevent galling, and protect surfaces. Clevis pins, cotter pins, and roll pins are critical in control systems, landing gear, and flight control linkages.

Procurement Challenges in Aerospace Fastener Sourcing

Obsolete and Hard-to-Find Parts

Legacy aircraft — particularly military platforms, regional jets, and classic general aviation aircraft — often require fasteners that have been discontinued by original manufacturers. When OEM channels run dry, finding a certified independent distributor with access to global surplus stock becomes essential.

Time Pressure

AOG (Aircraft on Ground) situations create extreme urgency. A single missing fastener can ground an aircraft, costing operators thousands of dollars per hour. This is why response time matters as much as part availability. Distributors who can confirm stock and provide quotes within 15 minutes give procurement teams a critical operational edge.

Counterfeit Risk

As demand for legacy parts rises and OEM supply dwindles, the counterfeit fastener market grows. Buyers must work exclusively with accredited distributors who perform incoming inspection, verify documentation, and provide guarantees on part authenticity.

What to Look for in a Fastener Distributor

When evaluating suppliers for aerospace-grade hardware, consider the following:

CriteriaWhy It MattersAS9120B CertificationConfirms aerospace-specific quality managementFAA AC 00–56B AccreditationIndustry-recognized standard for aviation parts distributorsTraceability DocumentationRequired for certified maintenance and manufacturingGlobal Inventory NetworkEssential for obsolete and hard-to-find partsResponse TimeCritical for AOG and time-sensitive procurementNo-China Sourcing PolicyReduces counterfeit and geopolitical supply chain risk.

The Bottom Line

Aerospace fasteners are small in size but enormous in consequence. Every bolt shear aircraft, every lock nut, and every panel fastener installed on a certified aircraft must meet strict standards — and that begins with choosing the right distributor.

For procurement professionals, MRO operators, and aerospace engineers looking for a reliable, certified source of aircraft hardware and fastener components, Fasteners Distribution offers access to an extensive global inventory with full traceability, competitive pricing, and rapid response times.

Browse the full catalog or submit an RFQ at fastenersdistribution.com.