CR3213-5-3 – CherryMAX® Blind Protruding Head Rivet (Nominal)
Available now through the AirParts Aero marketplace.
Overview Section
The Cherry Aerospace CR3213-5-3 (often written as CR3213-5-03) is a high-strength structural blind rivet featuring a universal protruding 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 the back side of the work is inaccessible.
The CR3213 series is the "Nominal" version, featuring a standard 5/32" shank diameter.2 It is widely used for original airframe assembly and standard repairs where the rivet hole remains within original tolerances. The CherryMAX system is famous for its "all-in-one" design, where the stem is mechanically locked into the sleeve, ensuring the fastener remains intact under heavy vibration and flight loads.3
Key Features Section
Mechanically Locked Spindle: Features a specialized locking collar that permanently secures the stem within the rivet sleeve. This prevents the stem from vibrating out, ensuring the rivet stays structural and eliminating Foreign Object Damage (FOD) risks.
Bulbed Blind Head: Upon 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.
Universal Protruding Head: Provides a large bearing area on the manufactured side, making it ideal for non-countersunk applications like fuselage skins, ribs, and brackets.
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 trimming.
Technical Specifications Section
| Specification | Detail |
| Part Number | CR3213-5-3 (CR3213-5-03) |
| Manufacturer | Cherry Aerospace |
| Head Style | Universal Protruding Head |
| Diameter | 5/32" Nominal (Actual: 0.156 - 0.160 in) |
| Grip Range | 0.126 in – 0.187 in (Size -03) |
| Sleeve Material | 5056 Aluminum Alloy |
| Stem Material | 8740 Alloy Steel |
| Hole Size Required | #20 Drill Bit (0.160 – 0.164 in) |
| Shear Strength | Approximately 835 lbs |
Aircraft Compatibility Section
The CR3213-5-3 is a foundational fastener for structural work on nearly all metallic aircraft:
Textron Aviation (Cessna/Beechcraft): Standard for structural patches, rib-to-skin attachments, and bulkhead repairs on Cessna 182, 210, and King Air models.
Piper Aircraft: Extensively used in the PA-28 and PA-32 series for wing spar and fuselage repairs.
Experimental Aircraft: A staple for Van's RV and Glastar builders for areas where a bucking bar cannot reach the backside of a 5/32" solid 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: Grip and Hole Size are Critical. Using a 5/32" rivet in a hole larger than 0.164" 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 (CR3243-5-3). Always verify material thickness with a Grip Gauge; if the rivet is too short, the bulb will not form correctly, and the joint will fail under load.
Technical Engineering Insight
The engineering value of the CR3213-5-3 lies in its Joint Preload Capability. Unlike standard pull rivets, CherryMAX technology uses the energy of the pull to expand the sleeve significantly before the stem fractures. This creates a high level of "clamping force" between the sheets, effectively mimicking the load-carrying characteristics of a bucked solid rivet.4 The steel stem is cadmium-plated to prevent galvanic corrosion with the aluminum sleeve and aircraft skin, ensuring long-term structural integrity in harsh environments.
Installation & Maintenance Addendum
Tooling: Use a high-quality power tool like the Cherry G704B or G747.5 While hand tools like the G29 can be used, the 5/32" 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.
Deburring: Always deburr both sides of the hole. Shavings trapped between the sheets will prevent a tight "pull-up" and compromise the shear strength of the repair.