4-axis CNC machining offers a significant upgrade over 3-axis machining. It adds an additional degree of freedom through rotational motion, making machining complex features possible and more straightforward.
In 4-axis CNC machining, the tool moves freely on the X, Y, and Z axes to machine the workpiece. However, the workpiece is not stationary on the table like in 3-axis machining.

A 4-axis CNC machine can rotate a workpiece around the X-axis in a plane called the A-axis. So as the tool moves along the workpiece and the table turns it, you can cut along the contour of the workpiece.
Because the table rotates around the X-axis, 4-axis CNC machines can produce intricately detailed parts. Additionally, the extra rotation makes it possible to access and machine parts on other faces at odd angles to create the final part. 4-axis CNC machines can access multiple faces of a workpiece without adjusting or changing fixtures. As a result, parts made from it are highly accurate and meet strict standards.
Most jobs done on a 4-axis CNC machine require only one setup. As a result, work can proceed smoothly without downtime or intervention to change fixtures and tools.
 Additionally, production costs are significantly reduced, especially when compared to 3-axis machining, since multiple fixtures are not required to hold the part.