Comparing Turning, Drilling, Milling, and Threading in Metal Machining

Under the title of metal machining, there are several different techniques. Machining is a versatile manufacturing process, so it is a good idea to become familiar with the various options available to you.

You may need some metal machining done on your projects, so keep reading to learn more about four of the most common machining processes.


Drilling is done by using a bit to cut a circular hole. This bit is often a multi-point, rotary tool used in various operations such as boring, reaming tapping, or countersinking.

As a cutting process, drilling is considered to be one of the more cost-effective solutions for metal machining.


Milling is done using multi-point rotary cutters. These cutters remove material from a piece. Face milling and peripheral milling are your two main choices here:

  • Face milling cuts flat surfaces, either horizontally or vertically
  • Peripheral milling cuts slots, gear teeth, or threads

On already machined parts, milling is most useful as a secondary process to define features or add finishings such as pockets, holes, or contours.


Threading is used for any product with connectors and fittings. Threads are a complex classification and require a lot of understanding, but the perfect example of threading is a bottle cap – the top of the bottle and the cap together offer a tight seal.

Internal (or female) threads and external or screw heads are your main elements and knowing how to cut these is an incredibly technical job.


The process of turning it exactly as its name suggests; the piece is turned while cutting tools move around it. This can be done as a manual or automated process, and the results are cylindrical shapes.

Manual turning requires constant supervision, automation with CNC programs does not. Type in your instructions and the computer program handles it all for you.

Metal Machining

With options available to you, you may be feeling unsure about the right metal machining process for your project. Luckily the team at Steelmor is knowledgeable and experienced. contact us today and speak to one of our friendly and professional staff.