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Explore our top-tier structural blind rivets and threaded inserts engineered for thin tube assemblies.
In modern industrial design, the transition toward lightweight materials and structures has made thin-walled tubes, hollow profiles, and sheet metals standard in manufacturing. Industries ranging from automotive and aerospace to solar racking and medical equipment rely heavily on circular, square, or rectangular tubing. However, assembly engineers face a persistent challenge: how do you add strong, reusable, load-bearing threads to a tube with a wall thickness that is too thin to tap?
Tapping threads directly into thin-walled tubes (typically under 3mm or 11 gauge) is practically impossible. The limited wall thickness provides only one or two thread pitches, which easily strip under minimal torque. Traditional solutions like welding nuts inside the tube are labor-intensive, require skilled operators, pose thermal distortion risks, and cannot be done on pre-painted or coated surfaces. This is where structural blind rivets and threaded rivet nuts emerge as the premier engineering solution.
Cold-forming installation avoids weld spatter, heat-affected zones (HAZ), and tube deformation.
Perfect for hollow tubes and closed profiles where the backside is completely inaccessible.
Knurled bodies and structural expansion deliver high resistance to spin-out and pull-out forces.
The mechanism behind adding threads to thin tubes using structural blind rivets (often referred to in the industry as blind rivet nuts or threaded inserts) is elegant yet robust. The process involves a pre-drilled or punched hole in the tube wall. The fastener is threaded onto the mandrel of an installation tool (pneumatic, hydraulic, or manual) and inserted into the hole.
As the tool is actuated, it pulls the mandrel back, causing the unthreaded sleeve portion of the fastener to expand radially outward and collapse against the inner wall of the tube. This forms a large, secure flange (or "bulge") on the blind side, clamping the tube wall tightly between the fastener's head and the collapsed sleeve. Once fully set, the tool reverses the mandrel out, leaving a clean, high-strength internal thread integrated directly into the thin tube.
For structural applications, these fasteners are engineered with features like knurled bodies or hexagonal shanks. A hexagonal hole completely eliminates the risk of the fastener spinning inside the tube under high torque conditions, while knurled round bodies bite into the parent material, providing excellent torque-out resistance in round holes.
In the automotive industry, the drive to reduce vehicle weight to improve fuel efficiency and EV battery range has led to the widespread adoption of aluminum and high-strength steel tubing. Structural blind rivets are extensively used to mount battery trays, cooling lines, structural brackets, and interior trim panels directly to the tubular space frames. Because these joints are subject to constant road vibration and dynamic loads, the fasteners must offer superior fatigue life and resistance to loosening. Stainless steel and high-grade steel blind rivets provide the necessary tensile strength and structural integrity without adding unnecessary weight to the chassis assembly.
Solar energy installations utilize galvanized steel or aluminum square tubes for mounting racking structures and tracker mechanisms. These structures are installed outdoors and subjected to extreme wind loads and thermal expansion cycles. Tapping threads into these thin-walled outdoor structures is prone to failure and accelerates corrosion. Using zinc-plated steel or stainless steel structural blind rivets ensures that the mounting brackets remain securely fastened over a 25-year service life, while the pre-applied coatings on the tubes remain undamaged during the cold-installation process.
Medical devices, such as hospital beds, surgical carts, and patient lifts, are constructed using thin-walled steel or aluminum tubing to keep the equipment light and maneuverable. These products require frequent disassembly for maintenance, cleaning, or configuration changes. Tapped threads would quickly wear out. Structural blind rivets provide durable, reusable machine threads that can withstand hundreds of assembly and disassembly cycles. Furthermore, the closed-end variants prevent fluids, cleaning agents, and contaminants from entering the interior of the hollow tubes, maintaining hygienic standards.
In modern logistics hubs, automated storage and retrieval systems (ASRS) and heavy-duty shelving units use complex tubular frameworks. These frames must support massive static loads and withstand the dynamic impacts of robotic shuttles. Structural blind rivets allow for rapid, modular assembly of these racks on-site. The high load-bearing capacity of carbon steel large flange blind rivets ensures that joints do not slip or deform under shear stress.
The global industrial fasteners market is experiencing a significant shift toward smart assembly and lightweighting. According to recent industry analyses, the demand for structural blind fasteners is growing at a CAGR of over 5.5%, driven by the aerospace, automotive, and electronics sectors. Key trends shaping the industry include:
When engineering a joint in a thin-walled tube, selecting the appropriate structural blind rivet requires careful consideration of several variables:
Material Compatibility: To prevent galvanic corrosion, the fastener material should closely match the tube material, or be isolated using coatings or washers. For aluminum tubes, aluminum or stainless steel fasteners are preferred. For carbon steel tubes, zinc-plated steel is the standard.
Grip Range: Each blind rivet has a specified grip range (the total thickness of the materials being joined). Choosing a fastener with a grip range that matches the tube wall thickness is critical to ensure proper expansion and clamping force.
Head Style: Flat head (or large flange) designs provide a larger bearing surface, distributing the load over a wider area, which is ideal for softer materials like aluminum or plastics. Countersunk heads are used when a flush surface profile is required for mating parts.
Real-world engineering scenarios demonstrating the performance of our structural fastening systems.
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