comparison between the mercury slip ring and pin slip ring

A slip ring is an electromechanical instrument that is used to join a fixed system with a rotary system. It is mostly used in applications that need rotation when they are transmitting electrical signals or power. It is used in several electrical gears to improve mechanical performance as well as to make the procedures easy and simple. The slip ring can be used in an electromechanical system that requires continuous and unrestrained rotation during the transfer of power or data from a constant to a rotating structure.

Configuration of Slip Rings

Slip rings have two main components, brush contact and metal ring. The number of brushes as well as the rings is determined contingent on the design as well as the application of the appliance. The rushes are secured with rotating rings and the rings rotate with fixed brushes. In both cases, the brushes keep contact with the ring by compressing springs. The brushes are static and fitted on the brush house. The rings are manufactured using conductive metals such as silver and copper. It is installed on the sheath but isolated with a central sheath. The rings are detached from each other by using plastic or nylon. Electric current flows through the brushes with the rotation of the ring. Therefore, you establish a continuous connection between the rings and the brushes.

Mercury Slip Ring vs Pin Slip Ring

The slip ring is available in different types to make it suitable for many various applications. Pin and mercury slip rings are common kinds of slip rings. If you are confused about whether to go for a pin slip ring or a mercury slip ring, here is a comparison of these two types of slip rings.

Mercury Slip Ring

Mercury Slip Ring

The mercury slip ring has to some extent similar performance to the electric slip ring. It acts as a conductive medium and helps to transmit current and energy signals through a liquid metal under normal temperature conditions. The role of the mercury slip ring is similar to any other kind of slip ring. The only difference is that the mercury slip rings use mercury to transmit electrical signals and data.

Here are some of the reasons to go for mercury slip rings. Let’s have a look at these reasons

High Stability

Mercury slip rings are the same in terms of performance as other electric slip rings. However, mercury slip rings benefit from contact with mercury as a conductive medium, which can transmit signals and current through liquid metal under normal temperature conditions. This type of slip ring has high stability and does not produce electrical noise.


Mercury slip rings provide the most economical, cost-effective, and informed rotary solution for various industries. Also, this type of slip ring can transfer a large amount of current regardless of its small size while keeping the cost low.

Low Maintenance

Mercury slip rings require little maintenance compared to the traditional slip ring. They have a smaller frame which can easily be adapted to any system. It also provides a streamlined and smooth mounting of the traditional slip ring, which is a bit complicated.

Low Contact Resistance

Connections of the slip rings are very conductive as mercury is used as a source of transporting the current. The contact resistance of the liquid to the electricity is zero, therefore providing perfect transmission. It is also a contributing aspect to low or insignificant electrical noise.

Long Service Life

The expenses of maintaining mercury slip rings are less as they are made using highly conductive as well as anti-corrosive materials. This decreases the contact friction force on conductive rings. Consequently, wear is reduced, which cuts the maintenance expenses, thus increasing the product’s life.

Pin Slip Ring

Pin slip rings are an alternative to mercury slip rings. Mercury is a chronic toxic substance. There is a significant potential threat to the environment and operators in the event of a leak. The pin slip ring is one of the types of slip ring where pin contact is used for establishing the connection. It is used in applications with small transmission space and where plug and play system is required by the device.

Here are some of the reasons to go for pin slip rings. Let’s have a look at these reasons

Beautifully Designed

Pin slip rings have a mercury-free and environmentally friendly design. The slip pin rings are exquisitely designed, and the wires are replaced by pins that meet the environmental requirements of PHS. This type of slip ring is widely used in cable reels, rotating platforms, hot rollers, and small wind turbines.

Easy to Handle

The slip pin ring has small dimensions, secure connection, and fixing advantages.  Slip pin rings are easy to handle because of their versatile design. It is generally chosen for packaging machines.

Higher Current Conductivity

Slip rings have a significant advantage, as they can be used for plugs and playmaking useful and flexible for use at home as well as in the industrial sector. Since the contacts used are made in the form of a pin; accurate contact is established, and the load capacity and current conductivity are higher because the connections used are mainly made of precious metals.

Smooth Transmission

The low wear in the pin slip ring is facilitated by the brushed surface of the conductive rings to allow smooth transport and low contact pressure on the rings. This reduces electrical noise and the possibility that parts will degrade and become blocked, obstructing the process of production.

Low Maintenance and Long Service Life

The maintenance cost of the slip ring is very low because dust and debris are lower due to reduced wear and, therefore, the regular maintenance requirements are low. With little maintenance, the cost of replacement parts is low ensuring long service life.

Summing it Up

Choose the best type of slip ring considering your requirements. If you are looking for cost-effective, low maintenance, and high stability, the mercury slip ring is a good option. If you are looking for a smooth transition and environment-friendly design, a pin slip ring is a good option.


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