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CR3242-4-05 – CherryMAX® Blind Flush Rivet (Oversize)
Part Number: CR3242-4-05
Manufacturer: Cherry Aerospace (A PCC Company)1
Military Specification: NAS1097 / MIL-R-7885
Overview Section
The CR3242-4-05 is a high-strength oversize structural blind rivet featuring a 100° flush (countersunk) head.2 It is part of the CherryMAX® family, the industry standard for "all-in-one" blind fasteners.3 The "42" designation indicates this is the oversize version of the rivet, specifically engineered for maintenance and repair environments where an original rivet hole has become enlarged or elongated.
With a nominal diameter of 1/8" (+ 1/64" oversize), the CR3242-4-05 provides a precision fit in reworked holes, restoring the structural integrity and load-transfer capabilities of the airframe skin and internal ribs. It features a mechanically locked spindle and a specialized "bulbed" blind head, making it an airworthy replacement for solid rivets in inaccessible areas.4
Enhanced Technical Data
| Technical Metric | Specification Data |
| Nominal Diameter | 1/8 in |
| Actual Shank Diameter | 0.140 in – 0.143 in (Oversize) |
| Grip Range (-05) | 0.251 in – 0.312 in |
| Head Style | 100° Flush Head (Reduced Profile per NAS1097) |
| Ultimate Shear Strength | 530 lbs (minimum) |
| Ultimate Tensile Strength | 245 lbs (minimum) |
| Sleeve Material | 5056 Aluminum Alloy (AMS 4118) |
| Stem Material | 8740 Alloy Steel (AMS 6322) |
| Finish | Chemical Film (Sleeve) / Cadmium Plate (Stem) |
Advanced Engineering & Structural Application
The CR3242-4-05 is designed for Hole-Fill Expansion. When the installation tool pulls the stem, the rivet sleeve expands to fill the entire cavity of the hole. In the case of this oversize rivet, the shank is slightly larger than a standard 1/8" rivet to compensate for wear or "rounding out" of the hole during the removal of the previous fastener.
Engineering Insight: The "Safe-Lock" Mechanism
The critical safety feature of the CR3242 series is the Locking Collar. As the rivet sets, a small gold-colored ring is sheared and forced into a groove in the stem. This creates a permanent mechanical lock, ensuring that the stem—which provides the majority of the rivet's shear strength—cannot vibrate out during flight. This effectively creates a "solid" fastener performance in a blind application.
Aircraft Compatibility
The CR3242-4-05 is a staple in Structural Repair Manuals (SRM) across a wide range of platforms:
Bombardier: Global, Challenger, and CRJ series for skin and fairing repairs.
Textron Aviation: Cessna Citation and Beechcraft King Air for airframe maintenance.
Boeing/Airbus: Secondary structures and interior floor grid repairs.
General Aviation: Essential for any metal airframe repair involving #27 drill size holes.
The Cherry Aerospace CR3242-4-05 is the professional's choice for airframe structural repairs where hole integrity is paramount. When a standard 1/8" rivet no longer fits securely, the CR3242 oversize series restores the tight-tolerance fit required for high-stress skins and pressurized structures. Featuring a 100° flush head for aerodynamic efficiency and a heat-treated steel stem for maximum shear load, this rivet ensures your repair meets or exceeds OEM specifications. Trust CherryMAX for "one-pull" reliability and permanent mechanical locking in every application.
Installation & Maintenance Addendum
Hole Preparation: This oversize rivet requires a #27 Drill Bit (0.144" - 0.147"). Standard #30 bits used for 1/8" rivets will be too small for the CR3242 shank.
Grip Verification: Use a Grip Gauge to ensure your material thickness is within the 0.251" – 0.312" range. An "under-grip" installation will prevent the blind-side bulb from forming against the structure, leading to a loose joint.
Visual Inspection: After installation, verify that the locking collar is fully seated in the head and that the stem fractured flush with the rivet head. If the stem is protruding, the rivet must be removed and the grip length re-verified.
