CR3552-4-02 - Cherry Aerospace Blind Rivet

CR3552-4-02 – CherryMAX® Blind Flush Rivet (Nominal)

Available now through the AirParts Aero marketplace.

Overview Section

The Cherry Aerospace CR3552-4-02 is a high-strength structural blind rivet featuring a 100° flush (countersunk) head.1 Part of the CherryMAX® family, this fastener is designed to provide the structural integrity of a solid rivet in areas where only one side of the structure is accessible (blind applications).

The CR3552 series is the "Nominal" version, utilized for original installations or repairs where the hole has not been enlarged. It features a 1/8" shank diameter and is specifically engineered for thin-sheet applications. The "all-in-one" design of the CherryMAX system ensures that the stem is mechanically locked into the sleeve, providing superior vibration resistance and shear strength.2

Key Features Section

• Mechanically Locked Spindle: Features a "Safe-lock" collar that permanently secures the stem within the sleeve.3 This prevents the stem from vibrating out (FOD prevention) and ensures the rivet remains a structural load-bearing member.

• Bulbed Blind Head: During installation, the sleeve forms a wide "bulb" on the blind side, distributing the load over a larger area. This is ideal for preventing pull-through in thin aluminum skins.

• One-Tool Installation: The integral driving anvil allows the rivet to be installed with a standard pulling head, eliminating the need for specialized nose-piece changes for different diameters.

• Flush Stem Fracture: The stem breaks off clean and flush with the manufactured head, maintaining aerodynamic smoothness without the need for secondary shaving.

• 5056 Aluminum Sleeve: Provides excellent corrosion resistance and is chemically compatible with standard aircraft aluminum alloys (2024, 7075).

• 8740 Alloy Steel Stem: The high-strength steel core provides the necessary shear strength to meet or exceed the ratings of solid AD-series rivets.

Technical Specifications Section

Aircraft Compatibility Section

The CR3552-4-02 is a standard structural fastener for a wide range of airframes:

• Textron Aviation (Cessna/Beechcraft): Frequently used for skin repairs and internal structural patches on the Cessna 172, 182, and 300/400 series.

• Piper Aircraft: Standard for repairs on the PA-28 Cherokee and PA-46 Malibu where blind access is required.

• Experimental Aircraft: A primary fastener for Van’s RV builders in areas like wing trailing edges or fuel tank baffles where bucking a solid rivet is impossible.

• Commercial MRO: Utilized in secondary structures and flooring panels for regional and narrow-body aircraft.

Technical Applications & Safety

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

Safety Warning: Grip range is critical. Using a -02 rivet in a stack-up thicker than 0.125" will result in an incomplete bulb formation on the blind side, leading to a weak joint. Conversely, using it in a stack-up thinner than 0.063" may prevent the locking collar from seating properly. Always use a Grip Gauge to verify your material thickness before selecting the rivet. For installation, a #30 drill bit is required to maintain the tight tolerances necessary for a structural interference fit.

Technical Engineering Insight

The engineering value of the CR3552-4-02 lies in its Joint Preload and Shear Capability. Unlike commercial pop rivets, the CherryMAX stem is designed to remain in the sleeve and take up a portion of the shear load. The steel stem is cadmium-plated to prevent hydrogen embrittlement and galvanic corrosion. Because the -02 is a "short" rivet, the internal mechanics are tuned to fracture the stem at a precise tension level that ensures the sheets are pulled together tightly (clamped) before the bulb forms, effectively mimicking the "upsetting" process of a bucked solid rivet.

Installation & Maintenance Addendum

1. Tooling: For the best results, use a Cherry G704B or G747 power puller. If using a hand tool (like the G29), ensure you pull straight; side-loading the stem during the pull can cause it to fracture unevenly.

2. Hole Deburring: Ensure both sides of the hole are deburred. Even a small burr can prevent the flush head from seating perfectly, which is critical for the aerodynamic requirements of high-performance aircraft.

3. Visual Confirmation: After installation, check for the gold-colored locking collar. It should be perfectly flush with the top of the rivet head. If the collar is missing or the stem is protruding, the rivet is not structural and must be replaced.

Product Specification:

Technical Datasheet [Click Here]