The use of boring mill machines enlarge the holes in different types of materials. The machine uses as tool with one cutting edge, but the machine itself comes in two different varieties. The Horizontal and Vertical boring mill machine.

  • Horizontal Boring Mill – This machine has a boring bar which rotates around a horizontal axis.  Similar to that of a horizontal milling machine. Additionally, a horizontal boring mill has a table which the workpiece rests on.
  • Vertical Boring Mill – This one is often referred to as a VTL. This machine works similar to a vertical lathe. The workpiece rotates around the vertical axis. In addition, at the same time, the boring tool moves in a linear direction – without turning.

What Do You Use A Boring Mill For? 

A boring mill machine is in use for hole enlargement requirements. People use it in place of other processes or machinery which may not be as efficient, accurate, or cost-effective as other machining processes. Some common uses for a boring mill include:

Finishing Internal Surfaces

Whether it’s smoothing them out or roughing them up, vertical boring mill machines can support with finalising the texture of a hole’s interior surface. This could be a new component or a product that is being reconditioned.

Boring Heat-Sensitive Components 

Using a shearing process, the boring mill machines can be used to enlarge the holes in components that are made from heat-sensitive or non-ductile materials. These types of materials will not be suitable for thermal and electric-based methods. For instance, laser cutting and EDM so manual boring machines are the ideal solution.

Benefits Of Vertical Boring Mill Machine 

Vertical boring mills can sometimes be compared to vertical lathes. Therefore, you may be wondering why you would opt for one and not the other. However, there are some benefits of boring milling machines that lathes don’t have.

Ability To Work With Large Parts 

Some applications will require the milling of large workpieces. This is where a vertical boring milling machine can help. For instance, Vertical boring mills can have much larger parts mounted on them than horizontal milling machinery.

Lowering Risk Of Tool Deflection

Tool deflection can take place when a tool undergoes too much resistance – an amount that is more than what it is able to compensate for. An example of this is when a spindle extends too far from the anchor. Consequently, leading to it drilling at the wrong angle when it is under pressure.

When it comes to boring mills, the spindle actually advances from the headstock. Therefore, it can be kept short and prevent tool deflection. As a result of this, you can guarantee more uniform drilling.


As with all pieces of machinery, naturally durability plays an important role in determining the quality of a finished product. If the machine working on the component is worn and shows signs of wear and tear, this could impact the overall quality and finish of the component. Here at PT Engineers, we take great care in ensuring that we maintain all of our machinery, so that we can keep delivering the highest quality work for our customers.

Vertical Boring Mill Machining Services

If you would like to find out more about our vertical boring mill or other CNC machining services, then head to our website today. Or, call 01788 543661 to speak to a member of our helpful and friendly team.

If you have found this blog helpful, then you may wish to read our previous blog: What Is Precision Machining?