What Is the Difference Between Sealed and Unsealed Rivets?

2025-09-16
Author: Rivmate Rivet

When choosing rivets, users often ask: What is the difference between sealed and unsealed rivets? This question seems simple, but it involves structural design, waterproof performance, and installation scenarios. Many engineers and purchasing personnel need to clearly determine which type of rivets is more suitable when dealing with applications such as outdoor, marine, or building curtain wall.

This blog will compare sealed rivets and unsealed rivets from three aspects: structural principles, performance differences, and typical application scenarios. It aims to help readers understand the core distinctions between the two and provide a clear decision-making basis for selection.

What Are Sealed Rivets?

Sealed Rivets (also known as Closed-End Rivets), are a special type of blind rivets that have a completely sealed tail after installation. Unlike ordinary open-type blind rivets, they do not leave any through holes, thus effectively preventing the penetration of liquids, gases, and impurities.

a. Main Characteristics

Air-tight and water-tight performance → After the riveting is completed, there are almost no leakage channels at the connection points.

Strong protective effect → It can prevent liquids, gases and dust from entering the joints, thereby enhancing the overall durability. Suitable for harsh environments → Often used in structures that are damp, highly corrosive, or require a sealed environment.

b. Typical Applications

Marine and Offshore Engineering: Prevent seawater infiltration and slow down corrosion.
Automotive Roof and Body: Prevent rainwater or moisture from entering the vehicle body.
HVAC System: Ensure air flow sealing and improve energy efficiency.
Outdoor Facilities: Such as solar support structures, curtain walls, and transportation equipment, ensure long-term waterproof performance.

Studies have shown that the assembly method using sealed rivets combined with sealant has a waterproof performance that is more than 40% superior to that of standard open-type blind rivets, and can significantly extend the service life of the structure.

What Are Unsealed Rivets?

Unsealed Rivets (also known as Open-End Rivets) are the most widely used type of blind rivets. Their structural feature is that a small hole will be left at the tail after installation, thus lacking the ability to resist water or gas.

Main Features

Simple structure → Composed of a rivet body and a pull core, with mature technology and high installation efficiency.
Low cost → Compared to sealed rivets, the manufacturing and procurement costs are lower, making it suitable for large-scale applications.
Reliable mechanical connection → It can provide sufficient shear and tensile strength to meet general assembly requirements.
Lack of sealing performance → It cannot prevent the penetration of liquids or gases, and is not suitable for waterproof or dustproof scenarios.

Typical Applications

Indoor lightweight structures: Such as furniture assembly, office equipment frames.
Electronic enclosures: Used for fixing non-sealed metal sheet enclosures.
Household appliances and industrial control equipment: Suitable for environments that are relatively dry and do not require long-term waterproofing.

In most non-outdoor and non-humid environments, non-sealed rivets remain the preferred choice for engineers due to their low cost and high assembly efficiency.

Sealed vs Unsealed Rivets: Key Differences

Feature	Sealed Rivets	Unsealed Rivets
Tail Structure	Closed	Open
Waterproof / Airtight	Yes	No
Corrosion Resistance	Higher (prevents liquid ingress)	Moderate
Cost	Slightly higher	Lower
Strength	Similar	Similar
Suitable Environment	Outdoor, humid, high-corrosion environments	Indoor, non-sealed structures
Typical Applications	Automotive, marine, facades, HVAC	Appliances, furniture, electronic enclosures

Tail Structure:
The sealed rivets have a closed tail, completely blocking the channels for liquid and gas penetration; the non-sealed rivets have an open tail, with a direct passage, resulting in a high risk of leakage.
Waterproof and Gasproof Performance:
During the 48-hour continuous water spray test, the sealed rivet joints remained dry; while the average leakage rate of ordinary non-sealed rivets exceeded 35%.
Corrosion Resistance:
In the neutral salt spray test (ASTM B117, 240 hours), the sealed rivet structure showed no obvious red rust; corrosion spots were commonly found in the pores of the non-sealed rivets.
Cost:
The single-piece cost of sealed rivets is usually 15% – 30% higher than that of non-sealed rivets; however, in the life cycle cost, due to the reduction in anti-corrosion maintenance, the overall cost is actually lower.
Strength:
There is little difference in the single shear strength between the two; common aluminum blind rivets have a strength of 1.5 – 3.5 kN, while steel blind rivets have a strength of 3 – 6 kN.
Applicable Environment:
The sealed rivets perform stably in high humidity or corrosive environments, with a lifespan that can be extended by 30% or more; non-sealed rivets are more suitable for low-risk indoor assembly.
Common Applications:
In the automotive industry, sealed rivets are commonly used on the roof and chassis to prevent water and mud from entering; in the appliance industry, non-sealed rivets are often used in electronic enclosures to reduce costs.

Industry Use Cases

The sealing requirements for rivets vary significantly under different working conditions. Through typical industry applications, the applicable ranges of sealed rivets and non-sealed rivets can be more intuitively understood.

a. Ship and Ocean Engineering

In ships and marine equipment, they are exposed to a high humidity and salt spray environment for a long time. The use of stainless steel sealed rivets can effectively prevent seawater from penetrating and extend the structural lifespan. Research shows that the sealed rivets can still maintain a joint without significant corrosion during the 480-hour salt spray test.

b. Car roof / Car body

The car roof and exterior sheet metal components are often exposed to rain erosion and vehicle vibrations. The use of sealing rivets can prevent water penetration and enhance the anti-corrosion performance. They are commonly found in the roofs of new energy vehicles and camper vans.

c. Building Facade

The building curtain walls and exterior facades need to withstand wind pressure, rain, and temperature fluctuations over a long period of time. Sealing rivets provide airtight and watertight protection in such scenarios, and their weather resistance can extend the service life of the curtain walls by more than 20%.

d. Electronic Enclosures and Household Appliances

Most electronic devices and home appliance casings are used indoors and have a low requirement for water resistance. Using non-sealed rivets can reduce costs and weight while maintaining structural strength, making them suitable for mass production.

User Concerns & Clarifications

① In terms of intensity, are there any differences between the two?

Under the same specifications, materials, and grip range conditions, the mechanical strength of sealed and non-sealed rivets is basically the same. The difference lies mainly in the sealing performance rather than the load-bearing capacity. Key points:

Refer to the data table. According to ISO 14589/IFI 114, compare the single shear/ tensile rated values of the rivets instead of “whether sealed”.
Core factors affecting strength: material (steel/stainless steel/aluminum), rod diameter and effective clamping thickness, whether “core retention/structural type”, hole quality and assembly stroke.
Engineering suggestion: Calculate the required number of rivets based on the maximum working load of the joint, and set a safety factor of 2.0 – 3.0; for vibration conditions, prioritize core retention/structural type blind rivets.

② Do all outdoor applications necessarily require the use of sealed rivets?

Strongly recommended. Especially in environments where there is rain, wind pressure, salt fog, and chemical media.

Direct Exposure: Roof, curtain wall facade, deck, top of cabinets → Choose sealing (Closed-End) or with sealing rings.
Humid Heat Cycle: Day-night temperature difference, presence of condensate water for a long time → Choose a sealed design and supplement with continuous glue application.
Corrosion environment: Coastal/chemical → Choose stainless steel or Monel material + sealed structure, and consider high corrosion-resistant coatings such as zinc-nickel/ALMAC/dacromet.
Exceptional scenarios: Completely indoor, non-waterproof structure, with a reliable secondary defense line (such as full circumferential welds or independent sealed chambers). Even so, the maintenance cost and leakage risk must be evaluated.

③ Are the costs significantly different?

The unit price is slightly higher (typically in the form of a percentage of two digits), but the life cycle cost is better.

Why is it more cost-effective?

Reduce rework: Once there is a leakage, the labor cost + downtime + material cost is much higher than the difference of the rivets.
Save processes: Compared to “open rivets + post-treatment with glue”, the integrated sealing rivets are more stable and have better controllability in terms of production rhythm.
Durability: The sealing structure reduces the failure probability caused by corrosion and water leakage.

Quick assessment formula:

TCO = Unit price of rivets × Quantity + Construction time cost + Expected rework cost.
When the rework rate or leakage risk cost is greater than the difference in rivet prices, the TCO of sealed rivets is significantly lower.

④ Can sealant be used instead of sealing rivets?

It can be used as a temporary substitute or as a secondary line of defense. However, its long-term reliability is inferior to that of sealed rivets.

Reasons and Approaches

Material aging: The sealant will age and shrink due to the influence of UV rays, temperature and humidity cycles, and the medium.

Construction Consistency: During the application process, there is a high probability of discontinuities/air pockets/unclean surfaces occurring, making it difficult to ensure 100% continuity of the seal.

Best Practices

Use sealing rivets as the main component, supplemented by continuous closed-loop adhesive application or EPDM/FKM sealing gaskets to achieve “double insurance”.
Select compatible adhesives such as neutral silicone/butyl/MS polymer/PU with the substrate; avoid using acidic silicone for sensitive materials like polycarbonate.
Standardize surface pretreatment (oil removal, drying, dust-free), control the compression amount at 20-30% (for rubber gaskets), and follow the curing time.

Verification: Before import, conduct spraying/water immersion/IP level test, and the corrosion resistance is verified according to ASTM B117/ISO 9227 salt spray test.

Rivmate Expert Recommendations

In the selection of rivets, environmental conditions and application requirements are the key considerations. Rivmate’s suggestions are as follows:

Damp, corrosive or waterproof environments → Preferentially choose Sealed Rivets. Their closed structure can effectively prevent liquids and gases from penetrating, thereby extending the service life.
Indoor or light-load, no sealing requirement applications → Unsealed Rivets are sufficient. They have a simple structure, are easy to install, and offer a more cost-effective solution.

Products and Support Provided by Rivmate

Sealed Rivet Series: Comprising aluminum, stainless steel and carbon steel materials, it is widely used in ships, car roofs and curtain wall systems, specially designed for waterproof and anti-corrosion purposes.
Unsealed Rivet Series: Economical and efficient, it is suitable for large-scale applications such as household appliances, electronic enclosures, furniture, etc.
Technical Support and Selection Consultation: The Rivmate technical team can provide customized selection suggestions and testing services based on material type, environmental conditions and mechanical requirements to ensure users obtain the optimal riveting solution.

FAQs

Q1: Is the strength of the sealed rivets higher than that of ordinary rivets?

Under the same material and specifications, the mechanical strength of sealed rivets is basically the same as that of ordinary rivets. The main difference lies in the sealing performance. Research data shows that the single shear strength of common blind rivets made of aluminum is approximately 1.5 – 3.5 kN, while that of steel rivets can reach 3 – 6 kN. Regardless of whether they are sealed or not, the strength difference is very small.

Q2: Can I apply sealant to non-sealed rivets to prevent water leakage?

Yes, but it is only suitable as a temporary or supplementary solution. Sealant will age over time and may fail due to exposure to ultraviolet rays, humidity, and temperature differences. In contrast, sealant rivets have their own sealing structure and can maintain watertight and airtight properties for a long time. Therefore, if the project is in an outdoor or high-humidity environment, it is recommended to directly use sealant rivets.

Q3: In a high-salt spray environment, are aluminum sealed rivets sufficient?

It is not recommended. Aluminum materials are prone to electrochemical corrosion in salt spray environments, especially when used in combination with steel or stainless steel. Tests have shown that ordinary aluminum rivets are prone to corrosion spots in the ASTM B117 240h salt spray test. In such environments, it is recommended to use stainless steel (A4) or Monel sealing rivets, combined with anti-corrosion coatings (such as zinc-nickel or ALMAC).

Q4: Can Rivmate provide a test report for water and gas resistance?

Yes. Rivmate can provide strength reports for rivets that comply with standards such as ISO 14589 and DIN 7337, as well as reports on waterproof/IP level tests and corrosion-resistant salt spray tests. This helps customers clearly understand the reliability of the rivets in the target application during the design and procurement stages.

Choose the Right Rivet Solution with Rivmate

Sealed rivets = Waterproof and airtight, suitable for demanding environments, such as in automobiles, ships, curtain walls and HVAC systems.
Non-sealed rivets = Low cost, suitable for non-sealed scenarios, such as in household appliances, furniture and electronic enclosures.

In actual engineering projects, the correct selection of rivet types will directly affect the lifespan and reliability of the structure. Rivmate offers a complete range of sealed and non-sealed rivets, covering various materials and surface treatments. Our technical team can provide selection guidance, testing support, and customized solutions based on your application requirements.

Contact us immediately to obtain our exclusive rivet application guide. Ensure that your project achieves the best balance between performance and cost.

Reference

The Difference Between Open and Closed End Blind Rivets and Their Uses

What Are Closed End Rivets?