Ring Terminals

A ring terminal is a short metal tube with a flat washer type ring attached. The tube or barrel end of the crimp is a hollow tube where the stranded wire is inserted and crimped. The contact or connection end is a flat ring with a central hole which connects to a stud or bolt. Ring terminals are insulated or non-insulated.

Ring terminals or connectors ensure a secure and reliable connection in electrical circuits, reducing the risk of disconnection and electrical failures. They provide excellent conductivity and are essential for maintaining stable and safe electrical connections in various applications.

How Ring Crimp Connectors Work

Ring crimp connectors provide a secure, solderless electrical connection. To use them, a stripped wire is inserted into the hollow barrel of the ring terminal. The barrel is then crimped using a crimping tool, creating a tight mechanical bond. The flat ring end, or crimp eyelet terminal, is placed over a screw or stud and fastened, ensuring a stable and reliable electrical connection. This method enhances conductivity and minimises the risk of wire disconnection, making electrical ring connectors or terminals ideal for automotive, industrial, and residential wiring applications.

Types of Ring Terminals

Crimp eyelet terminals are available in a wide variety of ring sizes and wire sizes. The CSA (cross sectional area) or AWG (American wire gauge) of the stranded wire is the most critical. Meanwhile, the size of the stranded wire must be adequately matched to meet the amperage. The size of the ring is matched to the bolt or stud size, usually in a metric measurement.

While ring and wire size are some of the first things to keep in mind, there are many other types of ring terminals to consider:

• Insulated Ring Terminals: These terminals feature an insulating sleeve that protects the connection from moisture, dust, and other contaminants, ensuring long-lasting and reliable performance. Insulated ring terminals are ideal for applications where electrical insulation and protection are crucial.
• Non-Insulated Ring Terminals: **Non-insulated **electrical ring terminals provide a cost-effective solution for general electrical connections. They allow for easy inspection of the crimp connector and are typically used in environments where insulation is not a primary concern.
• Heat Shrink Ring Terminals: These terminals come with a heat shrink sleeve that, when heated, provides additional insulation and strain relief. Heat shrink ring terminals are perfect for environments exposed to harsh conditions, providing extra protection against vibrations and abrasions.
• High-Temperature Ring Terminals: Designed to withstand extreme temperatures, these terminals are made from materials that resist heat and ensure reliable performance in high-temperature applications, such as automotive and industrial machinery.
• Heavy-Duty Ring Terminals: Built to handle higher current loads, heavy-duty electrical ring connectors are used in applications requiring robust and durable connections, such as large electrical machinery and power distribution systems.
• Shrouded/Unshrouded Terminals: Shrouded ring terminals have a protective covering that provides additional safety by preventing accidental contact with the terminal. Unshrouded ring terminals lack this covering and are used in applications where this level of protection is not necessary.

Other characteristics to consider include:

• Contact Material: The material used for the contact area of the terminal affects its conductivity and corrosion resistance. Common materials include copper for its excellent electrical conductivity and aluminium for its lightweight properties.
• Contact Plating: Terminals often feature plating, such as tin or gold, to enhance conductivity and provide corrosion resistance. Tin-plated ring ring terminals are widely used for their affordability and adequate protection, while gold-plated ring connectors offer superior conductivity and resistance to oxidation, ideal for high-performance applications.

Components and Construction of Ring Lug Terminals

Ring lug terminals are composed of several key components, each made from different materials chosen for their specific benefits:

• Barrel: Made from copper or aluminium, the barrel is where the wire is inserted and crimped. Copper offers excellent conductivity, while aluminium is lightweight and corrosion-resistant. The crimping process ensures a tight, reliable connection between the wire and the electrical ring terminal.
• Ring: Constructed from durable metals, the ring provides a secure connection point to screws or studs. This ensures a stable mechanical and electrical connection, essential for maintaining circuit integrity.
• Insulation Sleeve: Often made from PVC or nylon, the insulation sleeve covers the barrel, protecting against electrical shock, moisture, and environmental factors. This enhances safety and prolongs the lifespan of the terminal.

The construction process involves crimping the barrel to the wire and securing the ring terminal to a stud or bolt, creating a dependable and efficient electrical connection.

Ring Terminal Insulations

Ring terminals are available as insulated or uninsulated. Whichever you choose will depend on your application.

Insulated Ring Terminals

Insulated ring terminals feature a protective sleeve made from materials like PVC or nylon, which covers the barrel of the terminal. This insulation protects against electrical shock, moisture, and environmental factors. DIN 46237 colour coding is the most popular type of insulated crimp connector. Colour coding is used to denote a wire size:

• Red 0.5 mm² to 1.5 mm
• Yellow 2.5 mm² to 6 mm
• Blue 1.5 mm² to 2.5 mm

Other colours are available.

Uninsulated Ring Terminals

Uninsulated terminals are bigger terminals. Uninsulated terminals connect to bigger studs and bolts. Uninsulated ring terminals have the capacity to accept larger stranded wire. More specialised tooling is required for these heavy-duty terminals.

Industrial Applications of Ring Terminals

Ring terminals, lugs and crimp eyelet connectors are widely used in various industrial applications due to their reliability, ease of use, and ability to provide secure connections. They are essential components in numerous electrical and electronic systems.

• Electrical Panels: Ring terminals are commonly used in electrical panels to connect wires to circuit breakers, fuses, and other components. Their secure connection ensures reliable performance and safety in high-power environments.
• Terminal Blocks: Employed in terminal blocks, ring lugs provide a stable and corrosion-resistant connection, facilitating easy circuit changes and maintenance. This is crucial for organised and efficient wiring in control systems.
• Wiring Harnesses: Ring connectors are integral to wiring harnesses in automotive and aerospace industries. They ensure stable connections in high-vibration environments, improving the durability and reliability of the electrical systems.
• Motor Controls: Used in motor control systems, ring crimp connectors provide robust connections that can handle high current loads, ensuring efficient motor operation and preventing potential electrical failures.
• Industrial Machinery: In industrial machinery, electrical ring connectors are used to connect various components, such as sensors, actuators, and control units. Their durable construction ensures long-lasting performance in harsh conditions.
• Renewable Energy Systems: Electrical ring terminals are essential in renewable energy systems, such as solar panels and wind turbines, for connecting various components securely and efficiently.
• Power Distribution Units: In power distribution units, cable crimp rings and round terminals ensure reliable connections that can withstand high currents, contributing to the stability and efficiency of power delivery systems.

How to Choose the Right Electrical Ring Terminals for Your Needs

Choosing the right electrical ring terminal for your needs depends on several factors.

Firstly, ensure the terminal matches the gauge of the electrical wire. Measure your wire using AWG or CSA standards, to guarantee a secure connection. Consider whether you need insulated ring terminals for protection against moisture and contaminants or non-insulated terminals for easy inspection.

The material and plating of the terminal are also crucial; high-conductivity materials like copper are ideal, and plating options such as tin can offer additional corrosion resistance. Lastly, consider the environmental conditions, such as temperature, vibration, and chemical exposure, to select the most suitable terminal materials and insulation types.

Buying Ring Terminals: Ordering & Delivery

RS Australia is a trusted supplier and distributor of electrical ring terminals, eyelet terminals, lugs, connectors and crimp connectors. Our range includes brands such as ABB, Molex, MECATRACTION, and more. To place an order online, simply browse our extensive catalogue, filter your preferred products based on our extensive specifications, and add to your cart.

RS Group offers fast delivery of chassis mount resistors. For more details on delivery services and fees, please refer to our Delivery Page.