CR3214-4-03 – CherryMAX® Blind Flush Rivet (Nominal)
Available now through the AirParts Aero marketplace.
Overview Section
The Cherry Aerospace CR3214-4-03 is a high-strength structural blind rivet featuring a 100° flush (countersunk) head.1 Part of the industry-standard CherryMAX® family, this fastener is designed to provide the structural integrity of a solid rivet in applications where only one side of the structure is accessible.
The CR3214 series is the "Nominal" version, featuring a standard 1/8" shank diameter. It is widely used in original airframe assembly and standard repairs where the rivet hole remains within original tolerances. The CherryMAX system is distinctive for its "all-in-one" design, which includes an integral driving anvil, a specialized sleeve, and a mechanically locked stem that ensures the fastener remains structural under extreme vibration and flight loads.
Key Features Section
Mechanically Locked Spindle: Features a "Safe-lock" collar that permanently secures the stem within the rivet sleeve.2 This prevents the stem from vibrating out, ensuring the rivet stays structural and eliminating Foreign Object Damage (FOD) risks.
Bulbed Blind Head: During installation, the sleeve forms a large, consistent "bulb" on the blind side. This creates a wide bearing surface, making it excellent for thin skins and providing high pull-through resistance.
100° Flush Head: Designed for countersunk holes to maintain an aerodynamic, smooth exterior surface on the aircraft skin.
High-Strength Materials: The combination of a 5056 aluminum sleeve and a heat-treated 8740 alloy steel stem provides an optimal balance of corrosion resistance and high shear strength.
One-Tool Installation: The integral driving anvil allows the rivet to be installed with standard pulling heads, streamlining the maintenance process.
Flush Stem Fracture: The pulling stem is engineered to break off flush with the top of the rivet head, ensuring a finished professional look without secondary shaving.
Technical Specifications Section
| Specification | Detail |
| Part Number | CR3214-4-03 |
| Manufacturer | Cherry Aerospace |
| Head Style | 100° Flush Head (Countersunk) |
| Diameter | 1/8" Nominal (Actual: 0.125 - 0.128 in) |
| Grip Range | 0.126 in – 0.187 in (Size -03) |
| Sleeve Material | 5056 Aluminum Alloy |
| Stem Material | 8740 Alloy Steel |
| Hole Size Required | #30 Drill Bit (0.129 – 0.132 in) |
| Shear Strength | Approximately 530 lbs |
Aircraft Compatibility Section
The CR3214-4-03 is a foundational fastener for structural work on nearly all metallic aircraft:
Textron Aviation (Cessna/Beechcraft): Standard for countersunk skin repairs, rib-to-skin attachments, and interior structural patches.
Piper Aircraft: Extensively used in the PA-28 and PA-32 series for aerodynamic skin repairs.
Experimental Aircraft: A staple for Van's RV builders for areas where a bucking bar cannot reach the backside of a 1/8" countersunk rivet.
Commercial Transport: Utilized in secondary structures and flooring support for Boeing and Airbus regional aircraft.
Technical Applications & Safety
The -03 grip length is engineered for a total material thickness (stack-up) of 1/8" to 3/16".
Safety Warning: Hole Preparation. Using a 1/8" rivet in a hole larger than 0.132" will lead to insufficient hole-fill, causing the rivet to "smoke" (vibrate and wear) over time. If your hole is slightly enlarged from removing an old rivet, you should move to the Oversize version (CR3242-4-03).
Grip Length Check: Always verify material thickness with a Grip Gauge before selection. If the rivet is too short, the bulb will not form correctly; if it is too long, the head will not seat flush, compromising the aerodynamic and structural integrity of the joint.
Installation & Maintenance Addendum
Tooling: Use a high-quality power tool like the Cherry G704B or G747.3 While hand tools like the G29 can be used, the steel stem requires significant force that can be tiring for large repair jobs.
Visual Confirmation: After installation, verify the presence of the gold-colored locking collar at the top of the rivet head. If the stem is protruding or the collar is not seated, the rivet is not airworthy and must be replaced.
Countersinking: Ensure the countersink depth is precise. If the countersink is too deep, the rivet head will "knife-edge" the skin; if it is too shallow, the rivet will sit high, creating drag and potential vibration issues.