Flat o-rings are sealing rings that feature rectangular or square profiles, also called torus shapes, as opposed to o-rings, whose profiles are round. Flat o-rings function similarly to o-rings in that they are used for gasket and high-pressure sealing applications, and can even fit in the same gland. There are some spaces that are not round, or are not suitable for round o-rings to seal. Therefore, flat o-rings are designed the way they are so they adequately seal spaces that are similarly shaped. Flat o-rings can also be referred to as square or lathe cut rings.
Once placed between two parts of a machine’s body during assembly, flat o-rings serve as a sealing mechanism. However, unlike their other o-ring counterparts, flat o-rings do not require as much pressure or squeezing for them to function properly. They can also be easily removed when it is time to replace them, which significantly minimizes maintenance down time. In addition, they require less friction, leading to reduced wear and tear and eliminating the necessity for lubrication. These characteristics enable flat o-rings to last much longer and cost less, especially in applications where abrasion is a main concern. Since flat o-rings feature corners, they can be used in addition to round o-rings to cover places that the round o-ring cannot reach. For example, flat o-rings can be used as a seal between the oil filter and oil housing of a car, as a flat o-ring has a larger surface area and provides more coverage when screwed in place. Aside from these specific cases, flat o-rings and round o-rings can be used interchangeably for most other applications.
Although flat o-rings work the same way as other types of o-rings, there are certain applications and pieces of equipment where flat o-rings are especially recommended for, such as rotary sealing. Other examples include hydraulic and pneumatic pieces of equipment. Examples of industries that use flat o-rings extensively include jewelry manufacturers and suppliers, water treatment facilities, chemical processing, oil refineries, and aerospace.
Flat o-rings that feature square or rectangular cross sections are fabricated by being cut out of extruded tubes, or by way of extrusion out of a square-shaped mold. Curing processes such as trimming or knife cutting give flat o-rings their distinctive shape. The curing process involves adding chemicals to the raw material while still in its molten state in order to alter the chemical properties of the final product. The cutting and trimming processes are carried out by machines that are equipped with distinctly-shaped blades that are used to create exact duplicates of a product. This process is also known as die cutting.
Flat o-rings are made from thermoplastic materials and elastomeric rubbers, such as Teflon, Viton, and silicone. Flat o-rings have s four-lobed design, which doubles their sealing surface compared to regular o-rings. They also have a smooth surface texture, thermal conductivity, tensile strength, a broad range of tolerable temperature, and an ability to seal under high pressures. However, they require an additional step in the fabrication process, as opposed to other types of o-rings, which simply undergo molding. Therefore, flat o-rings are not as easily found as other styles.
O-rings are a highly versatile component. They can function as a screw support, as a cushion, as a leak barrier, and many other applications. Whether it is flat or round, there are numerous uses for o-rings. One particular industry for which flat o-rings are used in the fishing industry, where they are used to stabilize bait. The o-ring is slid around the bait, and the hook is hooked through the o-ring, as opposed to the alternative method where the bait itself goes through the hook. If live bait is held by an o-ring, it stays alive, making it more likely to attract fish. Depending on the ring’s size, they can hold live bugs, live worms, or pieces of meat. In addition, the use of a flat o-ring minimizes the likelihood of the fish catching the bait and escaping the hook. Fishers can benefit from this method because they do not have to replace bait as often.
Manufacturers of o-rings recommend flexible rings made from flexible plastic or rubber for fishing applications. Non flexible flat o-rings are much more likely to break during fishing. Polyurethane, latex rubber, and silicone are ideal for fishing applications because they are non-toxic, and thus will not contaminate the fish’s body with toxins. Because flat o-rings can play such an important role in fishing, there are some manufacturing companies that make o-rings especially for this purpose. O-ring suppliers and manufacturers will work with you to find the best o-rings suitable for fishing.
More Flat O-Rings
Flat O-Rings – Arizona Sealing Devices, Inc.
Flat O-Rings – Continental International, Inc.
Flat O-Rings Informational Video