Rack and pinions are used for lifting mechanisms (vertical movement), horizontal movement, positioning mechanisms, stoppers and also to permit the synchronous rotation of several shafts in general industrial machinery. On the other hand, also, they are found in steering systems to change the direction of cars. The characteristics of rack and pinion systems in steering are the following: simple framework, high rigidity, small and lightweight, and excellent responsiveness. With this system, the pinion, mounted to the steering shaft, is definitely meshed with a steering rack to transmit rotary movement laterlly (transforming it to linear movement) to ensure that you can control the wheel. Furthermore, rack and pinions are utilized for many other purposes, such as playthings and lateral slide gates.
As a mechanical component to transfer rotary into linear movement, gear racks are often compared to ball screws. There are benefits and drawbacks for using racks instead of ball screws. The benefits of a equipment rack are its mechanical simplicity, large load carrying capacity, and no limit to the space, etc. One drawback though is the backlash. The benefits of a ball screw are the high 
precision and lower backlash while its shortcomings are the limit in duration due to deflection.
There are applications where the gear rack is stationary, as the pinion traverses and others where the pinion rotates on a fixed axis as the gear rack moves. The former is used Spur Gear Rack broadly in conveying systems as the latter can be utilized in extrusion systems and lifting/lowering applications.
To provide many variants of rack and pinion, KHK has many types of equipment racks in stock. If the application takes a long duration requiring multiple gear racks in series, we’ve racks with the tooth forms properly configured at the ends. These are described as “equipment racks with machined ends”. When a gear rack is produced, the tooth cutting procedure and the heat treatment process can cause it to try & go out of true. We are able to control this with unique presses & remedial processes.