Week 9B: Metal Lathe


We will now move from the wood lathe to the metal lathe.  The basic principles are the same, but it is a different machine, new techniques, and working with new materials.


Metal Turning

Instead of turning wood on a lathe, we will be turning metal and machinable plastic.  Instead of using chisels and being in direct contact with the material, we will be using very hard tooling and dialed in operations.  We will have the ability to make parts very accurate and precise.

Chain Reaction clip – the only movie I know where the action hero is a machinist.


Straightforward shaped aluminum turnings.



  • Material should be secured by the 4 jaw chuck correctly (similar to the wood lathe 4 jaw chuck).
  • Always use cutting oil, better to use more than less.
  • Always wear eye protection.
  • Take small shallow cuts.
  • Never turn a long piece that is not supported by the tail stock.
  • Clean Up Everything
  • Never leave tooling out, especially the chuck key

This is a loaded gun.  I never want to see this again.



Instead of using chisels, very hard tooling is clamped to the lathe moved via dials and handles.



Facing is the process of removing metal from the end of a workpiece to produce a flat surface.




Turning is the removal of material from the outer diameter of a rotating cylindrical workpiece. Turning is used to reduce the diameter of the workpiece, usually to a specified dimension, and to produce a smooth finish on the metal. Often the workpiece will be turned so that adjacent sections have different diameters.




The alignment between the headstock and tailstock of the lathe enables you to drill holes that are precisely centered in a cylindrical piece of stock.  For accurate center holes a center drill is used.



 Tapping Threads in Metal

Cutting screw threads into material is accomplished with a tap set.  This video shows great technique.



Parting uses a blade-like cutting tool plunged directly into the workpiece to cut off the workpiece at a specific length. It is normally used to remove the finished end of a workpiece from the bar stock that is clamped in the chuck. Other uses include things such as cutting the head off a bolt.




Boring uses the boring bar to enlarge and true up a hole by removing material from internal surface.



We have plenty of 1″ diam aluminum rod in the shop (under the CNC) and plenty of 1.9″ diam aluminum tubing (speed rail) all over the floor.  You can use the metal cutting circular saw (NOT the wood cutting circular saw) in the shop to cut them down.

We also have some brass, but get used to the aluminum first.


In Class Demo

Mounting material in metal lathe

Turning aluminum: turning, facing, parting, drilling, tapping, boring

Metal Cutting Circular Saw


Skill Builder

You will be perform some basic operations on the metal lathe.  Facing, turning, parting, drilling, and tapping.



Machining a do-dad.



Related Reading/Viewing

Black Badger Advanced Composites

Build a Sonic Screwdriver

Milling Master Makes Mesmerizing Masterpieces

US Tap and Drill Bit Size Table

List of Drill and Tap Sizes

Lathe Cutting Tools

Mr. Pete’s YouTube Channel

Precision – Chris Bathgate

Chris Bathgate Metal Sculptor