Many of us tend to group companies that manufacture metal items in metal together under the banner of general 'engineering'. When you think about it however many components in aircraft engines, scientific or medical machinery for example are likely to be very small, specific, and vitally important in terms of what is at stake in terms of human health and suffering if they are not accurate or strong enough, or not of the right quality.
Engineering companies that manufacture components of this type may also need to manufacture these components in large quantities with no margin of error in them and without deviations in specifications or the high level of quality that customers expect and demand. This underscores the importance of several important factors that help define a precision engineering service.
While this is important in precision engineering, it is something that is important to all engineering. However, CNC milling and lathes have helped maintain a good level of accuracy.
Sounds obvious, but that's not the same as accuracy. While accuracy is how close you can get a measurement to a value, precision is about having a system that can repeat or reproduce a measurement under the same conditions, giving you the same result.
Predictability and control
This is one of the reasons why one hit CNC Milling has become so sought after. Each product is worked on with the same tools, by the same program in the same conditions so that the predictability and engineering precision can be closely maintained. There are time savings and cost savings from the simultaneous performance of different tasks, the energy efficiency of modern milling machines, and the fact that only one machine needs to be set up and operated.