MS20426
Countersunk Rivets
Mumbai · India
Why a Flush Head Genuinely Matters
A protruding rivet head disturbs airflow across an aircraft skin surface — a small effect on any single fastener, but multiplied across the thousands of rivets covering a wing or fuselage, that drag adds up to a real, measurable fuel efficiency and performance cost. MS20426’s 100-degree countersunk head solves this directly: the skin panel is pre-countersunk to match the rivet’s angle, and once driven, the rivet head sits flush with the surrounding surface rather than standing proud of it.
That flush requirement is exactly why installation technique and countersink depth control matter so much more for MS20426 than for a protruding-head rivet. Too shallow a countersink leaves the head standing slightly proud, reintroducing the drag the design is meant to eliminate; too deep, and the rivet head sits recessed with insufficient material to properly clamp the joint. Getting the countersink and rivet length matched correctly is the practical skill that determines whether the flush surface actually performs as intended.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our countersunk rivet range is manufactured to correct head angle and shank dimension tolerance, verified under our ISO 9001:2015 quality system.
Where This Standard Genuinely Applies
Genuine Aerodynamic Benefit
Flush head eliminates drag-inducing surface protrusion across large riveted skin areas.
Lightweight Aluminum Alloy
2117-T4 and 2017-T4 alloys chosen specifically for weight-sensitive aircraft structure.
Consistent Head Angle Tolerance
Controlled 100° angle ensures proper fit into a correctly countersunk hole every time.
Verified Shear & Shank Dimensions
Batch testing confirms genuine shear strength and shank diameter control for reliable installation.
MS20426 Alloy Options Explained
Standard Icebox Rivet Alloy
Can be driven directly at room temperature without heat treatment or refrigeration — the most common choice.
Higher-Strength Alloy
Higher shear strength than 2117-T4, but requires heat treatment and refrigerated storage before driving.
100° Countersunk Head
Standard flush head angle matched to standard aircraft skin countersink tooling.
MS20426 Flush Rivets vs Protruding Head Rivets
Confirming whether the surface is aerodynamically exposed determines whether the flush head genuinely earns its place over a simpler protruding-head rivet. This table is the quick reference we use with buyers before quoting.
| Aspect | MS20426 Countersunk | MS20470 Protruding Head |
|---|---|---|
| Head Profile | Flush, 100° countersunk | Domed, standing proud |
| Pre-Drilling Requirement | Countersunk hole required | Straight drilled hole only |
| Best Suited For | External aerodynamic surfaces | Internal structure, non-exposed areas |
| Installation Sensitivity | Countersink depth is critical | Less installation-critical |
MS20426 Specification Details
Materials We Manufacture In
- Aluminum Alloy 2117-T4 (Standard)
- Aluminum Alloy 2017-T4 (Higher Strength)
- Finish Anodized / Chromate
- Corrosion-Resistant Options Available on Request
How Countersunk Rivets Are Made
- Process Cold Headed
- Head Angle 100° Controlled Tolerance
- Testing Shear Strength / Dimensional
- Quality Batch Sampled
Available Dimensions
- Shank Diameter 1/16″ – 3/8″ (Inch Series)
- Length Custom to Grip Range
- Head Angle 100° Standard
- Metric Equivalent Available to Drawing
Application Areas
Wherever a flush, aerodynamically clean external surface is the actual requirement.
Aircraft Wing & Fuselage Skin
surface riveting
Control Surface Assembly
rudder skin panels
Defense & Military Aircraft
flush riveting requirements
General Aviation Manufacturing
and structure riveting
Aerospace MRO & Repair
rivet replacement work
Marine & Naval Aviation
aviation procurement
Drone & UAV Structure
skin riveting
General Flush-Surface Riveting
an aerodynamically clean surface
Standard Export Documentation
Prepared as standard practice for every MS20426 rivet shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification for every lot.
Shear Strength Test Records
Batch-level testing confirming genuine shear strength within specification for the ordered alloy.
Certificate of Conformance
Confirms the shipment matches the purchase order alloy/size specification in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
NABL Accredited Test Reports
Independent mechanical and dimensional testing available on request for critical applications.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Internationally Recognised Standards Coverage
Related Fastener Grades & Materials
MIL-N-25027 Self-Locking Nuts
Our aerospace self-locking nut specification for threaded joints elsewhere in the airframe.
View MIL-N-25027 →MIL-I-8846 Helical Coil Inserts
Our thread reinforcement specification for aluminum aircraft structure.
View MIL-I-8846 →Titanium Grade 5 Fasteners
Our aerospace-grade titanium fastener range for higher-load airframe applications.
View Titanium Gr5 Fasteners →Fasteners Manufacturer & Exporter to the USA
Our broader capability manufacturing to ASTM/ASME and US federal/military standards.
View USA Export Guide →Need a Genuinely
Flush Aerodynamic Surface?
Tell us your skin thickness, alloy requirement, and grip range — we’ll confirm the right rivet size and quote across our full countersunk range. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in