Shaft Keys that Reduce Manufacturing Costs and Machine Downtime

Feather Keys: The Forgotten and Ignored Drive Component A simple mechanical part can reduce manufacturing costs and machine downtime. • Engineers can choose from a wide range of shaft keys to transmit torque in power-transmission systems. • Feather keys are relatively unknown but offer durable, cost-effective designs. With all of the new components and materials bombarding engineers these days, some simple but effective ways of the past have been pushed aside. Take, for instance, shaft keys - sometimes called sunk keys - that transmit torque between shafts and shaft-mounted components such as gears or pulleys. Shaft keys come in a wide range of types and styles, including parallel, Woodruff, taper, Gib-head, and perpendicular versions. But some, such as the feather key, are all but forgotten. Here's why engineers striving for durable and cost-effective designs should consider them again. Parallel keys are sometimes called straight keys and include square and rectangular styles. They are the most common keys used today. The shaft usually has a slot running its full length to accommodate the key, or a slot longer than the key starting at the shaft end. Installation involves lining up keyslots in the shaft and component and then pressing in the parallel key. , as the name suggests, have square cross sections. They are normally specified for shafts with 0.25 to1.0-in. diameters but larger square keys are available for shafts up to 6.5-in. diameter. Designers use them when they want greater key depth than is possible with rectangular keys. , sometimes called flat keys, are general-purpose components for shafts between 1.0 and 20-in. diameter. Their width exceeds the height, letting them transmit more torque without adding slot depth to the shaft or keyway depth to the component. Shafts over 11-in. diameter that use rectangular keys are often milled flat along their length,