Lathe Machine Parts – A Quick Guide

In this article we will give an overview of the components of a lathe; the lathe machine parts and their primary functions. Lathes refer to a reductive machining tool where material is removed using in cutting, drilling, turning and sanding. One primary feature of a lathe is a single axis around which a piece of material is spun. Throughout history, the lathe has been a very important tool in the production of metal and wooden goods.

Uses

Lathes are used to create products which are radially similar (around the central axis), these products can range from dowel rods and baseball bats to steel pins and connectors. A lathe works by spinning a round/square/hexagonal bar of material, typically called rod stock, around its central axis and uses cutting tools which are in a fixed place to reduce the excess material to create the product. There are a wide variety of tools available which can attach to the lathe machine parts to produce a different variety of effects from smoothed or sharp corners, boring channels, drilled holes, and shaving material.

Different types of lathes

There is are a variety of different types of lathes which, while very similar, can produce a variety of different effects. The most common type of lathe is a center lathe (often called bench or engine lathe as well), often used with a single cutting implement or hand tools. Turret lathes are different in that they are used for rapid production of duplicate parts. The turret refers to a set series of cutting tools which in rapid succession can perform several different cuts and operations onto the rod stock. This allows a single operator to do multiple operations without setup or verification processes between steps. The final lathe we will discuss is the Multispindle, which are also now frequently called CNC machines. Through the use of computer controls, these production machines are typically high volume and low operator input. The Multispindle expands on the capabilities of a turret lathe by automating the changes between heads and accurately controls the production of parts. As the CNC lathes become more advanced they can now utilize multiple angles (multi-axis) to machine from as well as a continual increase in the accuracy of computer controlled tools.

Lathe Machine Parts and Components

Explanation of the primary lathe machine parts of a center lathe:

Bed: The heavy and rigid frame onto which all of the components are mounted. The bed is typically made of made of cast iron or hardened steel. It is important that the bed be incredibly durable as to not bow during production.

Ways: Ways are the guide rails which the tailstock rests and moves in. Both the inner and outer rails are machined to be parallel to keep movement accurate across the bed.

Headstock: The component of a lathe which rotates the rod stock. It utilizes a chuck to hold the stock in place, it is typically mounted into the inner way in a permanent manner.

Gearbox: Located on the inside of the headstock, the gearbox is used to translate the rotational motion into different speeds.

Spindle:  A hole in the back of the headstock assembly through which the rod stock is fed.

Chuck: A multi-jaw clamp to hold the rod stock in place while it is being machined. These can either be self-centering or independent of based on the number of jaws. Can be modified to mount oddly shaped workpieces that are not round/square/hexagonal.

Tailstock: Sits into the inner way of the bed. The railstock can be moved along the channel to lock into any position, to adjust for varying lengths desired from the final product. It can be mounted with cutting tools to add a taper or chamfer to the back of the piece.

Carriage: Sits into the outer ways of the bed. The carriage is used to mount and adjust cutting tools.

Cross Slide: Mounted on the outside of the carriage, the cross slide adjusts up and down to use a wheel to bring tooling into the workpiece.

Tool Post: The tool post is a spot to mount different cutting bits which are clamped into the tool holders that the cross slide uses.

Compound Rest: The compound rest is mounted to the top of the cross slide. It  to The compound rest axis can be adjusted by pivoting around the tool post, independently of the cross-slide or carriage.

Apron: The apron is fixed to the front of the carriage, it contains the mechanisms for moving the carriage and the cross slide.

Feed Rod: The primary power transition mechanism to move the carriage along the axis of the lathe. It will have two reversing gears attached to a piston to move the carriage forward or reverse.

Lead Screw:  A driveshaft with adjustable gears used primarily for the cutting of threads.

Steady Rest: Can be clamped into the ways, it contacts the bottom or sides of the workpiece to assist aligning it. Typically used to support a longer or unstable part.