A shaft collar is a mechanical fastener that goes around a shaft or rod with a screw or clamp to fix it in position. These devices are used for a number of functions, ranging from spacing elements on a flag pole to acting as stops in a drive train. Manufacturers of shaft collars typically offer a wide array of products and can custom fabricate components for special applications where mass-produced supplies will not work correctly.
One and two piece shaft collar designs are available. In both cases, the fastener collars the entire shaft, and may vary in length and diameter. Most take the form of small rings. Technicians can clamp the device into place by running a screw through the collar and into the shaft, or by clamping to distribute the pressure more evenly and reduce the risk of damage to the shaft. Two-piece designs may fasten along the sides to lock down onto a shaft.
These components are typically made from durable metals that can withstand high operating stress and a variety of conditions. In addition to functioning as mechanical stops, they can attach components to a shaft, and may be used for positioning, limiting, and spacing activities, depending on the system. They can also act as couplers. The strength is determined by the materials used and the size, and can be customized to applications with unusually high stresses.
Shaft collars are a critical part of many mechanical systems. They can come in a number of finishes to resist corrosion, limit conduction of electricity, and perform other functions. The attachment points are typically recessed to reduce the risk of injuries from protruding screws. Some designs may have screws that extend beyond the edges of the collar for specific functional reasons, usually by request from a customer.
Replacement shaft collar components are available for systems with failing or fatigued parts. It is important to purchase a part of the correct size and load tolerance to avoid problems, and to install it properly to limit the risk of problems like a crack in the shaft. If a particular shaft collar design is no longer in routine production, a custom order may be possible, or a company could determine if it has any back stock it could sell. Costs for custom components tend to be high, although companies may be able to get bulk discounts if they order multiple shaft collar sets to have spare parts available in the future.