Daniel Jones

Before bolts dominated aircraft assembly, rivets built aviation. The B-17, the DC-3, the Spitfire — all held together by millions of hand-driven solid rivets. And rivets haven't gone anywhere. They're still covering fuselage skins, wing panels, and control surfaces on virtually every aircraft flying today.

Here's what you need to know about the three rivet families that matter in modern aerospace.

🔩 Solid Rivets — The Classic That Still Dominates

Solid rivets are a single piece of metal driven from one side and bucked from the other, deforming the tail into a shop head that permanently clamps the joint.

Two head styles cover most applications:

AN426 Countersunk — flush with the surface, used on exterior skin where aerodynamic smoothness matters. Fuselage exterior, wing upper surface.

AN470 Universal Head — rounded protruding head, faster to install, used in interior structural joints where drag isn't a concern.

Most common material? 2117-T4 Aluminum (AD rivets) — the workhorse of aluminum airframe assembly. Drive them straight out of the bag, no refrigeration needed. For higher-stress joints, 2024-T4 (D rivets) step up the strength — but they need to be kept cold after heat treatment and driven within a time window or re-treated.

For composite and titanium structures, titanium rivets are required to avoid galvanic corrosion between the rivet and the base material.

🪛 Blind Rivets — One Side Only

Can't reach the back of the joint? Blind rivets solve that. You insert from one side, a setting tool pulls the mandrel through the rivet body, the blind end expands into a bulb head, and the mandrel breaks off at a pre-engineered break point. Joint set. One side. Done.

Standard pull-type blind rivets handle light structural and non-structural work. For primary structure, CherryMAX structural blind fasteners (NAS1738/NAS1739) are the aerospace standard — they include a locking collar that captures the mandrel after installation so it can't vibrate loose in service.

Critical detail for procurement: Grip range must match your material stack-up exactly. Too thin — the blind head forms wrong. Too thick — the rivet can't fully set. Always verify before ordering.

⚙️ Hi-Lok Fasteners — Precision + Built-In Torque Control

Hi-Lok is technically a two-piece fastener — a threaded pin and a collar — but it installs with rivet-like speed and consistency.

Here's the clever part: the collar has a hexagonal wrenching section that shears off at the exact correct torque value. No torque wrench needed. No overtorque. No undertorque. When the hex breaks off, the fastener is correctly installed. Every single time.

This makes Hi-Lok ideal for high-volume production environments where installation consistency across thousands of fasteners is critical and torque wrench access is limited.

Hi-Lok comes in aluminum, titanium (HL18/HL19), and A286 stainless for high-temperature applications. Used in wing-to-fuselage attachments, spar joints, composite panel assemblies — wherever you need high shear strength AND precise clamp load.

Related variants worth knowing: Hi-Tigue (cold-worked shank for better fatigue life) and Hi-Lite (reduced shank for weight savings). Not interchangeable — always spec per drawing.

📋 Quick Application Reference

Exterior aluminum skin → AN426AD countersunk solid rivet

Interior frames/bulkheads → AN470AD universal head solid rivet

One-side access panels → CherryMAX structural blind (NAS1738)

Primary structure, high shear → Hi-Lok titanium pin + collar (HL18/HL19)

Composite panels → Hi-Lok or CherryMAX in titanium

High-temp nacelle areas → Monel or A286 solid/blind rivets

📦 Sourcing Reality Check

Solid aluminum rivets — strong availability, multiple manufacturers, commodity pricing.

Hi-Lok titanium pins and CherryMAX structural fasteners — shorter qualified manufacturer lists, lead times running 8–16 weeks in some categories. Plan ahead, qualify a second source before you need it.

And always check documentation: CoC, Material Test Report, process certs. A rivet without a paper trail is not an airworthy rivet.

Need AN, CherryMAX, or Hi-Lok rivets with full traceability? World of Fasteners stocks across all three families with AS9120B-compliant sourcing and fast RFQ turnaround.

If you work in aerospace or defense procurement, Amphenol part numbers are basically unavoidable. MIL-DTL-38999 circular connectors, EMI filter connectors, high-current Class L cylindricals — they show up on drawings, BOMs, and MRO lists constantly. And for good reason: Amphenol has been building high-reliability interconnects for military and commercial aerospace platforms for decades.

Here's the thing though — Amphenol's catalog is massive, and part numbers are highly configuration-specific. A single character change in a D38999 part number can mean a completely different insert arrangement, shell finish, or contact plating. That's not a cosmetic difference — it's a functional one. You can't just order the closest-looking number and hope it mates correctly.

The product families you'll source most:

MIL-DTL-38999 Series III is the big one — the most widely specified cylindrical connector in aerospace and defense. Shell sizes 9 through 25, hundreds of insert arrangements, available in MIL-SPEC and commercial high-speed configurations. If you're doing avionics, flight control, or weapons systems work, you know this part number prefix by heart.

MIL-DTL-22992 Class L covers high-current applications — 40 to 200 amperes — in a robust cylindrical format for power distribution, ground power units, and heavy military vehicle electrical systems.

EMI/EMP filter connectors are Amphenol's answer for systems where electromagnetic hardening is a design requirement. The filter is integrated inside the connector housing, which eliminates the need for bulky external filtering hardware.

Miniature and micro-miniature connectors — the 2M Micro 38999, Bantam Micro-Bayonet, Warrior Grip — are the direction the market is moving for UAV, satellite, and next-gen avionics where weight and size constraints are driving connector selection as much as electrical performance.

What trips people up in procurement:

Ordering adjacent part numbers without checking every character of the configuration string. Assuming a physically similar connector is functionally equivalent. Not flagging counterfeit risk on MIL-SPEC cylindricals — these are well-documented counterfeit targets. And not requiring COC and manufacturer trace documentation from the distributor on every order.

A commercial aircraft has over one million fasteners holding it together. Bolts carry the most critical load — fuselage frames, engine pylons, landing gear, wing attachments. Get the wrong bolt into a flight-critical joint and you don't have a quality problem. You have a safety event.

So let's talk about what actually separates an aerospace bolt from the hardware store variety — and why it matters whether you're an engineer, a procurement specialist, or just someone who finds this stuff fascinating.

Hardware Store Bolt vs. Aerospace Bolt — What's Actually Different?

It comes down to three things: documentation, tolerances, and materials — all three, at the same time.

A standard bolt holds shelves together. An aerospace bolt is manufactured to a specific drawing revision, traceable to a material heat lot, processed only by certified shops, and shipped with paperwork proving all of the above.

The bolt itself generates a controlled clamping force — called preload — that must stay within a defined range through years of thermal cycling, vibration, and fatigue loading. That's what keeps an aircraft together at 35,000 feet.

The Three Bolt Standards You'll See Everywhere

AN Bolts (Army-Navy) The oldest standard — dating back to WWII. Still widely used in general aviation and legacy military platforms. General-purpose, well-stocked, and reliable. Not close-tolerance, so they're best where precise hole-fit isn't critical.

NAS Bolts (National Aerospace Standard) Step up in precision. Close-tolerance NAS bolts are designed to fill the hole precisely — critical for fuselage skin joints and wing attachment fittings where shear loads need to transfer without any movement. Also available in internal wrenching designs for tight spaces.

MS Bolts (Military Standard) The workhorse of US defense aerospace procurement. Required for DoD-contracted platforms. MS21250 series (alloy steel) and MS21259 series (corrosion-resistant steel) are among the most commonly specified bolts across military aircraft programs.

Materials — Titanium, Steel, or Superalloy?

Titanium (Ti-6Al-4V) — The modern standard for structural aerospace bolts. About 45% lighter than steel with comparable strength. Dominant on commercial and military platforms, commanding over 42% of the aerospace fastener materials market in 2025. Costs more, worth it in primary structure.

Alloy Steel (4340, 8740) — Landing gear, engine mounts, structural fittings where weight isn't the priority. Heat-treated to 180 ksi tensile strength is the common baseline. One catch: high-strength steel above 180 ksi needs post-plate baking to prevent hydrogen embrittlement — always check the cert.

A286 Stainless (Superalloy) — High-temperature applications near engines, exhaust systems, up to 1,300°F. When the environment is both hot and corrosive, A286 is the go-to.

Real Talk: Supply Chain Is Still a Problem

Lead times for specialty titanium aerospace bolts are currently running 6 to 12 months. Manufacturing disruptions in 2025 wiped out a significant share of US aerospace fastener supply — and the ripple effects are still being felt.

Smart procurement teams are responding by qualifying second sources early, locking in blanket purchase agreements for high-velocity part numbers, and building safety stock — while watching expiry dates on coated bolts so shelf life doesn't become another headache.

Before You Accept a Bolt Shipment — Check These

Part number AND revision match the drawing

Certificate of Conformance with lot number and spec reference

Material Test Report tracing back to the heat lot

Process certs from NADCAP-accredited shops

Head marking matches the standard — mismatched markings are a counterfeit red flag

Not all aerospace parts distributors are created equal. The certifications they hold — or don't hold — can mean the difference between a compliant, airworthy aircraft and a catastrophic failure.

Here is what the key certifications actually mean for buyers:

ISO 9001:2015 The global gold standard for Quality Management Systems. An ISO-certified distributor operates under a structured, audited framework — meaning every part is traceable, every process is documented, and quality is consistent across every order.

AS9120B Built specifically for aerospace distributors. Goes beyond ISO 9001 with strict aerospace-specific requirements around counterfeit part prevention, supplier control, and product traceability. If your distributor doesn't hold this, look elsewhere.

FAA AC 0056B An FAA-issued accreditation that verifies a distributor's supplier qualification process, storage conditions, documentation control, and counterfeit part detection. Essential for MRO operators, airlines, and defense contractors.

Buying from a non-certified distributor puts you at risk of counterfeit parts, audit failures, legal liability, and in the worst case — aircraft safety incidents.

ASAP Buying holds all three certifications — AS9120B, ISO 9001:2015, and FAA AC 0056B — and is the only independent distributor with a no China sourcing policy. With 30M+ parts and same-day shipping, it is built for procurement teams that cannot afford to compromise on quality.

The aviation industry depends on one thing above almost everything else: having the right parts available when they are needed.

Whether it's a commercial airline, an MRO facility, or a private aircraft operator, delays in obtaining replacement components can lead to grounded aircraft, maintenance disruptions, and increased operational costs.

In recent years, sourcing aircraft parts has become more difficult due to:

✈️ Global supply chain disruptions

✈️ Longer manufacturer lead times

✈️ Increased demand for aerospace components

✈️ Obsolete and hard-to-find parts

Because of these challenges, aviation buyers are turning to online sourcing platforms that provide quick access to extensive inventories and fast RFQ services.

Modern procurement solutions help buyers search by part number, manufacturer name, NSN, or other identifiers, reducing the time needed to locate critical components.

When it comes to military aviation, every component matters. From jet engines to hydraulic valves, the parts that keep defense aircraft flying come from a handful of world-class manufacturers. Here is a quick breakdown of the top names in military aircraft components and why they matter to defense procurement teams.

Boeing builds some of the most iconic military platforms — the F/A-18 Super Hornet, AH-64 Apache, and CH-47 Chinook. Beyond complete aircraft, Boeing produces airframe structures, avionics, and propulsion parts widely used across military fleets.

Airbus Defence and Space manufactures the A400M Atlas military transport and supports NATO fleets with a wide range of airframe and structural components sourced through NSN-based procurement systems.

GE Aviation powers some of the most advanced fighter jets and transport aircraft in service today. Its turbine components, engine housings, and exhaust systems are frequently sourced for MRO and depot-level maintenance.

Honeywell Aerospace dominates military avionics, auxiliary power units, and navigation systems. Its APUs are especially critical for operational readiness across U.S. and allied fleets.

Eaton Aerospace specializes in hydraulic systems, fuel systems, and motion control components found in combat aircraft, transport planes, and helicopters across NATO forces.

Texas Instruments supplies microprocessors and integrated circuits embedded in targeting, navigation, and communication systems used across defense platforms.

Sourcing these parts requires a certified distributor with proper CAGE Code traceability and compliance documentation. ASAP Buying stocks parts from all these manufacturers with 10 million+ NSN numbers, same-day shipping, and 15-minute RFQ turnaround.

The aviation industry relies on millions of individual components to keep aircraft operating safely and efficiently. From commercial airlines and cargo operators to military fleets and maintenance organizations, every operation depends on having access to the right parts when needed.

However, sourcing aircraft parts has become increasingly challenging in recent years.

Supply Chain Challenges Continue to Impact Aviation

Global supply chain disruptions have affected manufacturers, distributors, and procurement teams across the aerospace industry. Many components now have longer lead times than before, making it difficult for organizations to maintain inventory levels and complete maintenance schedules on time.

For procurement professionals, this means planning ahead and working with reliable sourcing partners.

The Growing Demand for Hard-to-Find Components

Many aircraft remain in service for decades. While this demonstrates the durability of modern aviation platforms, it also creates sourcing challenges when older components become difficult to locate.

Procurement teams frequently search for:

Obsolete aircraft parts

Long lead-time components

Aviation hardware

Electronic components

Defense and aerospace products

Finding these items often requires access to extensive inventory networks and experienced sourcing specialists.

Why Quality Matters

Aircraft parts are not like ordinary industrial components. Every part must meet strict quality and compliance requirements.

Before purchasing any aviation component, buyers should verify:

✔ Product traceability

✔ Documentation availability

✔ Quality assurance procedures

✔ Supplier reliability

Maintaining high sourcing standards helps support safety, operational efficiency, and regulatory compliance.

Technology Is Changing Aircraft Procurement

Modern procurement platforms have simplified the sourcing process.

Today, buyers can:

Search parts online

Submit RFQs quickly

Access large inventories

Compare sourcing options

Reduce procurement timelines

Digital procurement tools help organizations save time while improving sourcing efficiency.

Looking Ahead

As aviation continues to grow, efficient procurement strategies will become even more important. Organizations that leverage trusted suppliers, digital sourcing platforms, and strong inventory networks will be better positioned to manage future supply chain challenges.

For businesses looking to source aviation, aerospace, defense, and electronic components, ASAP Buying provides access to an extensive inventory network designed to support modern procurement requirements.