CR3214-4-02 - Bombardier Cherrymax OEM 100 Degree Flush Shear Head Rivet

CR3214-4-02 – CherryMAX® Blind Flush Rivet (Nominal)

Available now through the AirParts Aero marketplace.

Overview Section

The Cherry Aerospace CR3214-4-02 (often listed as CR3214-4-2) is a high-strength structural blind rivet featuring a 100° flush (countersunk) head. This fastener is a critical component in the Bombardier aerospace supply chain, used extensively for airframe repairs and assembly where aerodynamics and high shear strength are required but the backside of the structure is inaccessible.

The CR3214 series is the "Nominal" diameter version, featuring a standard 1/8" shank. The CherryMAX system is the industry standard for "all-in-one" blind fasteners, incorporating a mechanically locked stem that provides structural performance comparable to solid "AD" rivets.

Key Features Section

• Mechanically Locked Spindle: A visible locking collar permanently secures the stem into the sleeve, preventing the stem from vibrating out (FOD prevention) and ensuring the fastener maintains its shear integrity.

• 100° Flush Head: Specifically designed for countersunk holes to provide a smooth, aerodynamic finish on the aircraft's exterior skin.

• Bulbed Blind Head: During installation, the sleeve forms a large "bulb" on the blind side, providing a wide bearing surface that is ideal for thin-sheet applications or composite materials.

• One-Tool Installation: Features an integral driving anvil, allowing various diameters and styles to be installed with a single pulling head, reducing tool-change downtime.

• Flush Stem Fracture: The pulling stem is engineered to break off perfectly flush with the rivet head, eliminating the need for secondary shaving or trimming.

• High-Strength Materials: Utilizes a 5056 aluminum alloy sleeve for corrosion resistance and a heat-treated 8740 alloy steel stem for maximum shear capability.

Technical Specifications Section

Aircraft Compatibility Section

The CR3214-4-02 is a primary fastener for Bombardier and other major airframes:

• Bombardier (Global, Challenger, CRJ): Used in secondary structures, fairings, and cabin interior floor panels.

• Textron (Cessna/Beechcraft): Standard for countersunk skin repairs on high-performance twins and turboprops.

• Experimental Aircraft: Frequently used by builders of high-speed kitplanes to ensure a smooth, drag-free exterior.

• MRO Facilities: A "stock-standard" item for structural sheet metal shops performing localized skin patches.

Technical Applications & Safety

The -02 grip length is specifically designed for thin material stack-ups between 1/16" and 1/8" total thickness.

Safety Warning: Avoid Under-Grip or Over-Grip. Using a -02 rivet in a material stack thicker than 0.125" will prevent the bulb from forming correctly on the blind side, resulting in a joint that can pull through under stress. Conversely, using it in materials thinner than 0.063" may prevent the head from seating flush or the locking collar from engaging.

Hole Precision: Always use a #30 drill bit. If the hole is enlarged during the removal of the old rivet, do not use this nominal fastener; instead, step up to the Oversize version (CR3242-4-02).

Installation & Maintenance Addendum

1. Tooling: For the best results in high-volume repairs, use a power tool such as the Cherry G704B. For field repairs, a G29 hand tool is adequate but requires more physical force due to the steel stem.

2. Deburring: Ensure the hole is deburred. Any metal shavings trapped between the sheets will prevent a tight "pull-up," leading to a gapped joint and reduced fatigue life.

3. Visual Check: After installation, verify that the gold-colored locking collar is seated flush in the head. If the stem is protruding or the collar is missing, the rivet is not airworthy and must be replaced.