What Is a Lathe and How Does It Work

July 26, 2020

Today we're going to answer a popular machining question:

What is a lathe?

If you're considering lathe work and want to learn more about what the tool does, you've come to the right place. Here are some lathe basics to help you understand what it is, how it works, and why it could be useful in your next project:

1. Lathe 101: What is a Lathe?

A lathe is a machining tool that is used primarily for shaping metal or wood. It works by rotating the workpiece around a stationary cutting tool. The main use is to remove unwanted parts of the material, leaving behind a nicely shaped workpiece.

There are many types of lathes that are specialized for different materials and techniques. Here at All Metals Fabricating, we have four different kinds of lathes, including a lathe with live tooling capabilities for multitasking jobs.

People have used lathes to make parts for other machinery, as well as specialty items like bowls and musical instruments. Whatever the type and function, they all operate using this basic holding and rotating mechanism.

2. Parts of a Lathe

The main parts of a lathe are the bed, headstock, tailstock, spindles, toolrest, and motor. Here's how it works:

The Bed Holds It All Together

All parts of the lathe are attached to the bed. This forms the base of the lathe and is one of the factors that determine the size of the piece. That is, the distance from the main spindle to the bed will tell you the maximum diameter limit.

Proper Orientation

The headstock should be on the left, and the tailstock should be on the right. If you're seeing the opposite, check and make sure you're not standing on the wrong side of the lathe.

The headstock is where the main action happens. This is where the power of the motor is applied to the workpiece. Part of its purpose it to hold the main spindle, so you should see this spindle here as well.

The motor can be found on the underside of the lathe bed, on the left near the headstock. It is often some type of electric motor, but a lathe can have a hydraulic motor as well.

Adjustable Parts

You can adjust the toolrest for height and rotation, but for safety reasons, you should only do this when the machine is off. Once you loosen it to adjust, double-check to make sure it's tightened again before continuing.

The tailstock is also adjustable, and you'll likely be able to remove it entirely. Just like with the toolrest, you should never make these adjustments when the lathe is in operation. There's more on this in the Lathe Safety section of this post.

Attachments and Accessories

The spindles, including the rotating main spindle that holds the workpiece, can be outfitted with different attachments and accessories. To allow for these fittings, the main spindle is often hollow and threaded on the outside.

Some useful attachments for the main spindle include centers, chucks, and faceplates. You can use these to position the workpiece and hold it in place. 

3. Who Should Use a Lathe?

Known as the "mother of machining tools," lathes can be used for a variety of purposes. These include shaping, drilling, sanding, knurling, turning, cutting, and deformation. This kind of versatility in a tool is hard to beat, and that's why so many metal- and woodworkers depend on lathes for the basis of their work.

If you need a precision cutting and shaping tool, a lathe might be perfect for your project. Lathes are good for teams that need a versatile piece of equipment capable of doing the work of multiple tools.

4. Lathe Safety

You should get comfortable with using a lathe if you want to use it well, but don't get too comfortable.

You know the moment when you're using a machine, doing some kind of repetitive motion, and your brain slowly switches to autopilot? As you might know from experience, these are the moments when mistakes occur.

These lathe safety guides from Purdue University and West Virginia University give some crucial things to watch out for:

Wear the Right Gear

If you're in a machine shop, you should already be wearing safety glasses with side protectors, or maybe even a face shield. If not, the right time to get equipped is before lathe operation.

Tie up your hair if it's long, and roll up any long sleeves. Never wear gloves, rings, or a watch while using a lathe. If any of these items get caught in the bit or spindle, you'll find yourself in a deadly situation fast.

Check the Shields and Guards

Make sure everything is in its correct place before you start using the lathe. If anything looks wrong, label it clearly before leaving the area. You can write something like, 'Out of Service.' You don't want anyone coming in after you to run into problems that you could have prevented.

Keep Your Tools Sharp

Dull and damaged lathe tools are not only ineffective—they're also dangerous to use. Label and fix before moving forward.

Power Off Before Making Adjustments

Never adjust the lathe as it's running. If you notice something you want to move, wait until the lathe is fully off before doing so. Likewise, if you need to perform any maintenance on the lathe, you should remove the power source completely beforehand.

Partnering with an Experienced Machine Shop

The biggest advantage when it comes to lathe safety is something that can't be easily fixed: experience and skill. If you find your own chops lacking, don't worry. All you need to do is find a good machine shop that knows what they're doing, and create a solid partnership to get the job done.

You're Ready to Use a Lathe!

So, what is a lathe?

A lathe is, among other things, a shaper, cutter, sander, and deformer. It takes attachments for specialty jobs and creates results precise enough to be used in other pieces of machinery. In short, a lathe is an essential piece of metal- and woodworking equipment and one of the most versatile tools out there.

Talk to us if you have any questions about this amazing tool, and find out what we can do for you!