Blind Rivets Explained: Aluminum vs. Stainless vs. Copper
If you're fastening metal roofing panels, trim, or flashing where you can't reach the back side of the material, you need a blind rivet. Choosing the right material (aluminum, stainless steel, or copper/brass) is what determines how long that joint lasts. This guide breaks down the differences between blind rivet types so you can match the rivet to your substrate, environment, and budget.
Quick Comparison
| Material | Best For | Corrosion Resistance | Relative Cost | Notes |
|---|---|---|---|---|
| Aluminum | General-purpose sheet metal, lighter-gauge panels | Good; forms protective oxide layer | $ | Lightweight, easy to set, most common dome head option |
| Stainless Steel (304SS) | Standard metal roofing, general exterior use | Very good | $$ | Widely used, available in dozens of painted colors |
| Stainless Steel (316SS) | Coastal, marine, high-chloride environments | Excellent | $$ | Higher molybdenum content resists salt-air corrosion |
| Copper / Brass | Copper roofing, gutters, and flashing | Good; matches copper substrate | $$$ | Prevents galvanic corrosion against copper materials |
What Is a Blind Rivet, and Why Dome Head?
A blind rivet is a two-piece fastener, a mandrel and a body, that can be installed entirely from one side of the material. That's where the name comes from. You drill a hole, insert the rivet, and pull the mandrel with a rivet tool. It expands the rivet body against the back side of the joint and then snaps off. That makes blind rivets essential for fastening joints without access to the reverse side of sheet metal, things like closing up trim, flashing overlaps, or attaching accessories to an installed panel. A dome head rivet has a slightly rounded head that spreads load over the material surface while shedding water rather than trapping it. That's why it's the standard head style for exterior metal roofing and siding applications.
Aluminum vs. Stainless: The Core Tradeoff
Aluminum blind rivets are the lightest and least expensive option, and they resist corrosion reasonably well on their own thanks to a natural oxide layer. They're a solid choice for general fabrication and lighter-duty sheet metal work where the rivet isn't under constant heavy load or extreme weather exposure. But aluminum is a softer metal, so it isn't the top pick where maximum pull-out and shear strength matter most.
Stainless steel rivets deliver higher strength and better long-term corrosion resistance, which is why they dominate the metal roofing and exterior construction market. Duco Plus's Stainless Steel Dome Head Blind Rivets are rated with a tensile strength of approximately 530 lbs and shear strength of approximately 420 lbs, and they carry corrosion resistance ratings of TAS114 Appendix E G85 Annex A5 (1000 Hour) and ASTM B117 (1000 Hour) salt-spray testing. They're also FBC 1506.6 and Miami-Dade County approved (L25-0521.11), which matters if your project needs to meet Florida or hurricane-zone code requirements.
Within stainless, the choice comes down to 304SS vs. 316SS. 304 stainless is the standard grade, excellent for most roofing and general exterior applications. 316 stainless includes added molybdenum, which significantly improves resistance to chloride and salt-air corrosion. If the job is within a few miles of the coast, around a pool, or exposed to de-icing salts, 316SS is the safer long-term choice even though it costs a bit more.
Copper and Brass: Solving the Galvanic Corrosion Problem
Copper and brass rivets aren't chosen for raw strength. They're chosen for metal compatibility. When two dissimilar metals stay in contact with moisture present, galvanic corrosion can eat away at the less noble metal over time. Copper or copper-alloy roofing, gutters, and flashing are especially prone to this if fastened with steel or aluminum rivets. Using a copper or brass rivet on copper substrate keeps the metals compatible and avoids that slow corrosion at every fastener point, which is critical on high-end architectural copper roofing where the fasteners need to last as long as the roof itself.
Real-World Usage Examples
- Standing seam trim closure: A contractor closing out end caps and hem seams on a standing seam metal roof uses stainless dome head rivets to fasten trim pieces where the back side is inaccessible.
- Coastal pole barn siding: A metal building installer near the coast specifies 316SS rivets instead of 304SS to withstand salt-air exposure on exposed fastener panels.
- Copper gutter and flashing work: A roofer installing copper gutters uses copper rivets at seams and joints to avoid galvanic staining and pitting against the copper sheet.
- Light-gauge ductwork and flashing: A sheet metal shop uses aluminum rivets for interior or lower-exposure fabrication work where cost and weight matter more than maximum corrosion resistance.
- HVAC and accessory mounting: A technician mounts an accessory bracket to an already-installed metal panel using a blind rivet because there's no access behind the panel.
Frequently Asked Questions
What's the difference between aluminum and stainless steel blind rivets?
Aluminum rivets are lighter and less expensive with good general corrosion resistance. Stainless steel rivets offer higher strength and superior long-term corrosion resistance, making them the preferred choice for exterior metal roofing applications.
Should I use 304 or 316 stainless steel rivets?
Use 304SS for standard exterior and roofing applications. Upgrade to 316SS for coastal, marine, or high-chloride environments where extra corrosion resistance is worth the added cost.
Why would I use a copper rivet instead of stainless?
Copper rivets are used to avoid galvanic corrosion when fastening copper roofing, gutters, or flashing. Pairing dissimilar metals like steel with copper can cause accelerated corrosion at the fastener.
What does "dome head" mean on a blind rivet?
A dome head rivet has a rounded head that distributes clamping load over the material surface and sheds water, which is why it's the standard style for exterior sheet metal and roofing fasteners.
Are Duco Plus stainless rivets code-approved for roofing?
Yes. Duco Plus's stainless steel dome head blind rivets are FBC 1506.6 and Miami-Dade County approved (L25-0521.11), with corrosion ratings of TAS114 Appendix E G85 Annex A5 and ASTM B117, both at 1000 hours.
Ready to choose the right rivet for your project? Browse the full range of aluminum and stainless dome head blind rivets at https://ducoplus.com/collections/rivets.