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How To Choose Between Spline Shafts And Key Shafts?

August 30, 2021

How To Choose Between Spline Shafts And Key Shafts?

Many machine assemblies require shafts that allow them to transmit energy through an entire gearbox. There are basically two kinds of shafts used for such operations, spline shafts and key shafts. Depending on the nature of your project, one will be more optimal than the other. 


Here's a short guide to help you pick between spline shafts and key shafts


Spline Shafts

A spline shaft is a mechanical part that has a number of equally spaced grooves on its surface, which is mated with another cylindrical member. These shafts can evenly transfer torque throughout many systems. Plus, they maintain the linear motion that vehicle manufacturers need. To ensure their durability and strength, most spline shafts are made using various alloys. 



These shafts guarantee the smoothest and the most silent operation possible while enduring high loads, especially the high-quality shafts manufactured by True Gear & Spline Ltd., the experts in gear and shaft design. Plus, they equally distribute the force along with their mated component. Helical splined shafts can deliver parallel and straight-angle power transfers, too.



Splines are expensive because they're much longer and sturdier than keyed shafts. Due to this size constraint, most businesses have to redesign their products to accommodate the shaft. Plus, splines require lubrication at all times to minimize friction and prolong their life.


Key Shafts

Key shafts look and operate like a lock-and-key system. The keyed shaft sits in the key seat and mates with its specially-designed keyway, which is connected to another component. As a result, the keyed shaft connects this component to the rotating machine element, such as an engine. The mated parts produce axial movement once the rotation begins.



Keyed shafts are much more affordable than spline shafts because of their size. In addition, there are set international standards defining the optimal operating capacity for all keyed shafts. Moreover, advanced key shafts allow manufacturers to customize their performance because they can easily mount and dismount them.



Most keyed shafts can only produce medium to low torque that is relatively lower than the torque produced by a standard spline shaft. In addition, its many connected parts can easily become disjointed during operation and potentially introduce load instability and shaft imbalance.


Hence, it is best to opt for spline shafts if higher torque is your requirement and you don’t mind an increase in machine size. Otherwise, key shafts are equally adept at producing sufficient torque and help in transmission. 


Contact us today at True Gear and Spline to get the best shafts and gears for your next project