Closed End vs Open End Rivet - Which Pop Rivets Are Better ?

2024-03-12
Author: Rivmate Rivet

For Pop Rivet, the performance differences between different structures of the same specification are extremely obvious. Closed-end vs open-end rivets – what’s the difference? Essentially, the main differences between closed-end (Closed-End) and open-end (Open-End) blind rivets lie in their sealing performance, mechanical strength, and cost efficiency. The former achieves waterproof and rust-proof effects by sealing the bottom, while the latter is known for its economy and versatility. This article provides an in-depth analysis of the structural principles, performance differences, and typical application scenarios of the two types, helping you quickly determine which rivet is the most suitable for your project.

Understanding the Structure of Pop Rivets

Blind rivets are a type of single-sided fastener that can achieve a secure connection without needing to access the back side. They are widely used in automotive, construction, sheet metal, and electrical assembly applications.

a. Core Components of a Pop Rivet

A standard Pop Rivet consists of three parts:

Body: Also known as the shell or sleeve, it is the main load-bearing part of the rivet and is typically made of aluminum, steel or stainless steel.
Mandrel: Passes through the interior of the cap body and is used to generate tension during installation, causing the tail of the cap body to expand and lock the material in place.
Break Point: Designed to break at the specified tension level to ensure consistent riveting and structural integrity.

During the installation process, the riveting gun pulls the core shaft to cause the tail end of the cap body to expand and clamp the workpiece, thereby forming a stable mechanical connection. The core shaft then breaks at the break point, with some parts remaining inside the rivet.

b. Single-Side Installation Principle

The greatest advantage of blind rivets lies in their “single-side operability”. The operator only needs to drill a hole on one side, insert the rivet, and use a riveting gun to complete the assembly. This feature makes it the most practical fastening method for enclosed structures (such as metal boxes, door frames, and equipment shells).

Compared with bolts or welding, the blind riveting structure not only reduces the installation time by approximately 40% – 60%, but also avoids the problem of material deformation caused by heat processing.

c. Closed-End vs Open-End Design Difference

The key difference lies in whether the bottom of the cap is sealed or not.

Open-End Type: The bottom of the cap is open, and the broken core shaft remains inside; there are still tiny pores after installation.
Closed-End Type: The bottom of the cap is completely sealed, and the broken core shaft is locked inside, thus achieving waterproof, gas-proof and anti-corrosion sealing performance.

This structural difference determines their different performances in terms of waterproofness, corrosion resistance and application fields. In Rivmate’s structural tests, the sealing effect of the closed-end rivets in the same environment can be more than 300% better than that of the open-end ones.

What Is an Open-End Rivet?

Among all the types of blind rivets, the Open-End Rivet (open-ended blind rivet) is the most common and widely used one. It is renowned for its simple structure, low cost, and high assembly efficiency, and can be found in almost all types of lightweight manufacturing and sheet metal assembly scenarios.

① Definition & Design Features

An open-end rivet refers to a standard rivet whose bottom of the cap body has an open structure. During the installation process, the mandrel is pulled by the riveting gun, causing the tail of the cap body to expand and clamp the material. When the mandrel breaks at the preset core breakage position, the broken end partially remains inside the cap body, while the tail remains in an open state.

Open-End Rivet refers to Standard Pop Rivet. It does not have waterproof or sealed structures, but it can meet the needs of most basic assembly requirements. The open-end rivets comply with ISO 14589 and DIN 7337 standards and are the most widely used category among all types of blind rivets, accounting for approximately 70% of the global rivet usage.

② Advantages of Open-End Rivets

Significant cost advantage: The structure design is simple and the production efficiency is high. It is the most economical riveting solution.
Fast installation: Standard electric or manual pull riveting guns can be used, and the entire process can be completed with a single pull riveting.
Stable clamping force: After expansion, it forms a stable mechanical locking force, suitable for various materials.
High versatility: It can be used for connecting aluminum, steel, stainless steel and plastic parts.

In the 3 mm aluminum plate assembly, standard 4.8 mm open-type rivets can achieve an average shear strength of 820 N and tensile strength of 680 N, which meets the requirements of general assembly conditions.

③ Limitations & Considerations

Although open-type rivets are economical and practical, they have certain limitations in specific circumstances:

No waterproof or sealing performance: The core shaft hole is of a through structure, allowing rainwater or moisture to enter the interior through the gaps.
Susceptible to corrosion: If exposed to damp or salt spray for a long time, the residual area of the core shaft is prone to rust formation.
Low seismic resistance: The core shaft is not locked, and strong vibrations may cause loosening or noise.
Not recommended for use in waterproof or long-term outdoor applications.

To enhance the anti-corrosion performance, you can choose the galvanized steel cap body or the aluminum + stainless steel core combination models; if the sealing requirement is high, you should consider using the Closed-End alternative.

What Is a Closed-End Rivet?

Among all types of blind rivets, the Closed-End Rivet is a structural type rivet specifically designed for sealing, corrosion prevention, and high-strength connections. Its key feature is that the bottom of the head is completely sealed (Closed End), and after the mandrel breaks during the riveting process, it is locked inside, thus forming a 100% sealed structure. This unique design makes the closed-end rivet one of the most reliable fastening solutions in environments that are waterproof, airtight, and resistant to corrosion.

① Definition & Structural Features

The main difference between the closed-type rivet and the ordinary open-type lies in that the bottom end of the cap body is closed. During installation, the mandrel is pulled, causing the tail of the cap body to expand on the back of the workpiece and form a clamping force. When the pulling force reaches the set value, the mandrel breaks at the break point, but it does not penetrate the bottom of the cap body; instead, it remains completely inside the cap. This means that the riveting point is completely sealed, preventing air, moisture, or oil from entering the connection area. The closed structure significantly improves the waterproof sealing grade (IPX7 and above) and reduces problems such as core shaft loosening due to corrosion or vibration.

② Advantages of Closed-End Rivets

The closed-end blind rivets are not merely a type of mechanical fastener, but also a “sealing engineering solution”. The actual test results from Rivmate show that, under the same specifications, the comprehensive durability of the closed-end type is enhanced by over 45% compared to the open-end type.

100% Waterproof & Airtight The closed bottom effectively blocks liquids, gases and dust from entering the pores, making it an ideal solution for waterproofing, dustproofing and oilproofing connections.
Secure Mandrel Retention The core shaft is locked inside by the cap body to prevent loosening, detachment or noise problems caused by vibrations.
Enhanced Corrosion Resistance The closed structure prevents water vapor from entering, and is particularly suitable for coastal, high-humidity or chemically corrosive environments.
Improved Structural Strength The core shaft remains inside, enhancing the overall shear strength by approximately 10–20% and providing excellent seismic stability.

In the ASTM B117 salt spray test, the closed-type stainless steel rivets can remain free from corrosion for 1000 hours, while the ordinary open-type begins to show oxidation and rust after only 240 hours.

③ Limitations and Considerations

Although the closed type has excellent performance, certain factors still need to be taken into consideration when choosing it:

High cost: Due to its complex structure and high manufacturing precision, the unit price is usually about 15–25% higher than that of the open type.
Limited clamping range: The closed bottom restricts the expansion space, making it more demanding in terms of matching the thickness of the workpiece.
High installation accuracy requirements: It is necessary to control the drill hole size and tension to avoid deformation of the cap body or incomplete sealing.

It is recommended to measure the total thickness of the material before installation, ensuring that it falls within the middle value of the Grip Range of the specified type of rivets, in order to achieve the best sealing effect.

Closed-End vs Open-End Rivet: A Complete Performance Comparison

When choosing a blind rivet (Pop Rivet), the structural differences between the closed-end and open-end types directly determine its performance in practical applications. It not only affects waterproofing, corrosion prevention and mechanical strength, but also determines the assembly cost and service life.

Comparison Item	Closed-End Rivet	Open-End Rivet
Waterproof & Airtight Seal	★★★★★ Completely waterproof and airtight; ideal for high-sealing applications	★☆☆☆☆ No sealing ability; water and air can penetrate easily
Corrosion Resistance	★★★★☆ Mandrel fully enclosed for anti-rust protection; suitable for humid or salt-spray environments	★★☆☆☆ Exposed mandrel prone to corrosion and water ingress
Mechanical Strength	★★★★☆ Mandrel locked inside body; higher tensile and shear strength	★★★☆☆ Standard strength; suitable for light-duty connections
Installation Difficulty	★★★☆☆ Requires precise control of thickness and hole size to ensure sealing	★★☆☆☆ Easy installation with wider tolerance range
Cost Efficiency	★★★☆☆ Slightly higher cost; value depends on corrosion protection needs	★★★★★ Lowest cost; ideal for mass production
Recommended Environment	Humid, outdoor, waterproof or anti-corrosive structures such as roofing, curtain walls, and HVAC systems	Indoor, lightweight, non-sealed assemblies such as appliances and interior fittings

Closed-End vs Open-End Rivet: Which Rivet Type Should You Choose?

Choosing the appropriate type of rivets depends on the usage environment, structural requirements and life cycle cost. Blind selection often leads to assembly failure or an increase in maintenance costs later on. Therefore, engineers should conduct scientific selection during the design stage based on environmental factors, protection requirements and material properties.

Application Scenario	Recommended Rivet Type	Key Reason
Roofing & Cladding Systems	Closed-End Rivet	Provides excellent waterproof sealing and corrosion resistance; prevents leakage and oxidation; ideal for long-term outdoor exposure.
Appliances & Decorative Panels	Open-End Rivet	Low cost and fast installation; suitable for non-sealed assemblies in dry indoor environments.
Outdoor & Marine Equipment	Closed-End + Stainless Steel	Offers superior salt-spray, rust, and corrosion resistance; maintains long-term structural stability in harsh environments.
Mass Production of Light Industrial Goods	Open-End Rivet	Mature technology with high installation efficiency; compatible with automated assembly systems.

Rivmate’s Final Recommendations

In the comparison of “Closed End vs Open End Rivet”, there is no such thing as the “best rivet”; there is only the “most suitable application scenario”. The existence of each structural design is to meet specific engineering requirements. Choosing the right rivet not only enhances the connection strength but also significantly extends the service life of the structure.

Rivmate Final Verdict

If your project is located in an outdoor, humid or salt-spray environment: Please choose the Closed-End Blind Rivets. They offer 100% waterproof, corrosion-resistant and gas-sealing protection, making them the preferred solution for building roofs, curtain wall systems and HVAC equipment.
If your project is in an indoor, lightweight assembly or non-waterproof environment: Please choose the open-end blind rivets. They have a simple structure, low cost and fast assembly speed, and are highly suitable for the home appliances, interior decoration and light industry sectors.
If you want to balance lightness and durability: It is recommended to use the aluminum cap + stainless steel core closed-type rivet (Al Body + SS Mandrel). This combination has demonstrated excellent strength, corrosion resistance and assembly efficiency balance performance in the Rivmate test.

Tested & Proven by Rivmate

Rivmate conducted long-term salt spray, shear and fatigue tests on different types of rivets:

Closed-End Rivet: Resistant to corrosion for 1000 hours in salt spray tests, with a 20% increase in shear strength.
Open-End Rivet: Cost-effective and suitable for mass production and non-sealed structures.

Rivmate Selection Criteria

Clearly specify the usage environment (dry/damp/outdoor/marine).
Determine the core requirements (waterproofing, strength, lightweight or cost priority).
Select the appropriate materials and structural types.
Refer to Rivmate performance data and standard test results to ensure long-term stability.

Technical Support

If you are still unsure which type of rivet is the best fit for your project, please feel free to contact the Rivmate engineering team.

We will provide you with a customized Rivet Selection Report and sample support based on your materials, working conditions and environmental requirements.

📧 Product Inquiry: manufacture@world-rivet.com

🌐 Official Website: https://worldrivet.com/