Aluminum Fastening Systems: Bolts, Rivets, and Joining Best Practices

Joining aluminum correctly is critical for durability, strength, and corrosion resistance. This guide covers the main aluminum fastening systems and when to use each.

Riveting

Rivets are permanent fasteners that join two or more aluminum sheets or extrusions by expanding a pin inside a collar.

• Solid rivets – lightweight, high strength, low cost; requires specialized rivet gun
• Blind rivets – faster, no back-side access needed; slightly lower strength
• Common in aircraft, marine vessels, and composite structures

Bolting

Bolts are removable and reusable, making them ideal for assembly and maintenance.

• Use stainless steel or aluminum alloy bolts to prevent galvanic corrosion
• Always use isolating washers between bolt head/nut and aluminum
• Tighten to spec – over-tightening strips threads
• Common in building frames, machine assemblies, and structural connections

Welding Aluminum

Welding creates strong, permanent joints but requires skill and equipment.

• GTAW (TIG) – precision, high-quality welds; slower, costlier
• GMAW (MIG) – faster, good for production; requires inert gas shield
• Filler metals – 4043 or 5356 alloy rods depending on base metal
• Risk: heat-affected zone loses some strength; proper cooling is essential

Adhesive Bonding

Modern structural adhesives (epoxy, polyurethane) are lightweight and reduce thermal bridging.

• Surface prep is critical – remove oxide and contaminants with mechanical or chemical treatment
• Cure time varies; some products require heat or humidity control
• Common in aerospace, automotive, and premium curtain wall systems

Choosing the Right Method

• Riveting – permanent, lightweight, no equipment needed at site
• Bolting – removable, easy maintenance, requires isolation against corrosion
• Welding – strong, fast in mass production, needs skilled labor
• Adhesives – modern, clean aesthetic, longer cure times

Corrosion Prevention

• Never use iron or copper fasteners directly on aluminum – galvanic corrosion will occur
• Washers and isolation sleeves protect joint areas
• Sealants around fastener holes prevent water ingress in exposed assemblies

See our products and corrosion protection guide for more detail on material selection and joint design.