shape, they are often called bushings. Bushings can be metal or plastic, or even air. Plain bearings can run on hardened steel or stainless steel shafting (raceways), or can be run on hard-anodized aluminum or soft steel or aluminum. For plastic bushings, the specific type of polymer/fluoro-polymer will determine what hardness is allowed. Plain bearings are less rigid than rolling-element bearings. Plain bearings handle contamination well and often do not need seals/scrapers. Plain bearings generally handle a wider temperature range than rolling-element bearings Plain bearings (plastic versions) do not require oil or lubrication (often it can be used to increase performance characteristics) Dovetail slides Dovetail slides, or dovetail way slides are typically constructed from cast iron, but can also be constructed from hard-coat aluminum, acetal or stainless steel. Like any bearing, a dovetail slide is composed of a stationary linear base and a moving carriage. a Dovetail carriage has a v-shaped, or dovetail-shaped protruding channel which locks into the linear base's correspondingly shaped groove. Once the dovetail carriage is fitted into its base's channel, the carriage is locked into the channel's linear axis and allows free linear movement. When a platform is attached to the carriage of a dovetail slide, a dovetail table is created, offering extended load carrying capabilities. Dovetail slides are advantageous when it comes to load capacity, affordability and durability. Capable of long travel, dovetail slides are more resistant to shock than other bearings, and they are mostly immune to chemical, dust and dirt contamination. Dovetail slides can be motorized, mechanical or electromechanical. Electric dovetail slides are driven by a number of different devices, such as ball screws, belts and cables, which are powered by functional motors such as stepper motors, linear motors and handwheels. Dovetail slides are direct contact systems, making them fitting for heavy load applications including CNC machines, shuttle devices, special machines and work holding devices. Mainly used in the manufacturing and laboratory science industries, dovetail slides are ideal for high-precision applications. Compound slides Slides can be constructed with two sections or multiple sections. A slide with two sections can only extend approximately 3/4 of the total compressed slide length. A compound slide typically has three sections: fixed, floating intermediate member, and the section attached to the equipment. A compound slide can extend at least as far as the compressed slide length and typically a bit more. In the case of rack slides, this