CR3522-4-04 - CherryMax Countersunk Rivet

CR3522-4-04 – CherryMax Countersunk Rivet

Available now on the Airparts.aero Marketplace.

Overview

The CherryMax CR3522-4-04 is a high-strength, "bulbed," locking spindle blind rivet, representing the pinnacle of structural fastening technology for aerospace applications. It is specifically designed to be installed "blind," meaning from only one side of the structure, providing a reliable joint with strength properties comparable to solid rivets. This rivet features a 100° countersunk head, allowing it to sit perfectly flush with the surrounding skin, which is essential for maintaining aerodynamic smoothness. The CR3522-4-04's robust multi-material construction and mechanically locked stem make it a premier choice for critical structural assembly and repair.

Key Features

• 100° Countersunk Head: Designed with a 100-degree flush head that fits into a standard countersunk hole. This creates a smooth, aerodynamically clean surface, reducing drag on aircraft skins, panels, and fairings.
• Mechanically Locked Spindle: Features the proprietary CherryMax "Safe-Lock" locking collar. This collar mechanically locks the stem into the rivet sleeve during installation, preventing stem loss from vibration and creating a vibration-proof, high-strength joint.
• High-Strength Multi-Material Construction: Engineered with a combination of high-strength materials for optimal performance:
  • Sleeve: Monel (Nickel-Copper Alloy) for excellent strength and corrosion resistance.
  • Stem: Corrosion Resistant Steel (CRES) for high tensile strength needed to form the rivet.
• Large Blind-Side Footprint: Designed to form a large "bulbed" footprint on the blind side of the structure. This wide bearing surface effectively distributes clamp-up force, making it ideal for thin sheet metal applications and preventing damage to composite materials.
• Controlled Grip Range: The "-04" dash number specifies a precise grip range (total material thickness) for which the rivet is designed, ensuring proper formation of the blind head and achieving full shear and tensile strength.

Technical Specifications

• Part Number: CR3522-4-04
• Component Type: Bulbed, Locking Spindle, Countersunk Head Blind Rivet
• Head Style: 100° Flush (Countersunk)
• Nominal Diameter: 1/8 inch (#4)
• Shank Diameter: 0.126 - 0.129 inches
• Grip Range (-04): 0.188 - 0.250 inches
• Materials: Monel Sleeve / CRES Stem
• NAS Standard: NAS9308M
• Installation Tool Requirement: Pneumatic or manual CherryMax pulling head (e.g., H701B-456) and hydro-shift riveter (e.g., G747, G704B).

Aircraft Compatibility

The CherryMax CR3522-4-04 is a universal structural fastener, not specific to one aircraft model, but is a standard repair and assembly component across the entire aviation industry in accordance with manufacturer's structural repair manuals (SRMs).

• Common Applications:
  • Skin & Panel Installation: Attaching fuselage, wing, and empennage skins where a smooth aerodynamic surface is required.
  • Structural Assembly: Joining ribs, stringers, and other internal structural components where access to the backside is limited.
  • High-Vibration Areas: The locked stem makes it ideal for use on firewalls, engine nacelles, and areas subject to high vibration where other fasteners could fail.

Applications

This rivet is the specified solution for creating strong, permanent joints where a flush finish is essential:

• Aerodynamic Surfaces: Its primary use is on external aircraft surfaces to minimize parasitic drag.
• Blind Structural Repairs: Allows for certified structural repairs to be made to areas like box beams or control surfaces where bucking a solid rivet is impossible.
• Thin Sheet Fastening: The large bulbed tail provides the necessary bearing support to achieve high clamp-up force in thin materials without damage.

Why Choose CR3522-4-04?

For structural applications requiring a flush finish, the CherryMax CR3522-4-04 offers unparalleled reliability and strength. Its mechanically locked stem provides a visually inspectable, vibration-proof joint that is a certified replacement for solid rivets in many applications. Unlike simpler "pop" rivets, the CherryMax is a true structural fastener, designed and tested to withstand flight loads safely. For any airworthy repair or assembly on an aerodynamic surface, the CR3522 is a globally trusted and certified solution.

Order Your CR3522-4-04 CherryMax Rivets Now

Execute your structural repairs with the certified, high-strength fasteners that define the aerospace industry. Visit Airparts.aero to order your CherryMax CR3522-4-04 blind rivets today.

The installation of a CherryMax CR3522-4-04 rivet is a precisely engineered process. A specialized pulling head grips the rivet's serrated stem. As the tool is actuated, it pulls the stem, causing the rivet sleeve to form a large, uniform bulb on the blind side of the material. This action draws the material sheets together, providing a high clamp-up force. As pulling continues, a locking collar on the stem is driven into a recess in the rivet head, mechanically locking the stem into the sleeve. This creates a solid, hole-filling assembly. Finally, the stem fractures at its designed break notch, ensuring a flush finish with the rivet head. The visible locking collar provides a key post-installation inspectability feature, confirming a successful and secure installation.

Note: This is a flight-critical structural component. It must only be installed where specified by an approved structural repair manual or other engineering disposition. Installation requires specialized CherryMax tooling. The selection of the correct grip length and the preparation of a clean, correctly-angled countersunk hole are critical for the strength and integrity of the final joint.