Lathe machines are among the most versatile tools in manufacturing and metalworking. They allow machinists to perform multiple operations, from shaping and cutting to drilling and finishing, all on a single workpiece.
Whether you are working with wood, metal, or plastic, understanding the types of lathe machine operations helps you achieve precision, efficiency, and high-quality finishes.
In this article, we’ll explore all the essential types of lathe machine operations, including primary cutting, threading, boring, drilling, finishing, and special-purpose operations.
Types of Lathe Machine Operations
- Turning
- Facing
- Chamfering
- Knurling
- Thread cutting
- Filing
- Polishing
- Grooving
- Spinning
- Spring Winding
- Forming
- Drilling
- Reaming
- Boring
- Counterboring
- Taper boring
- Tapping
- Undercutting
- Internal thread cutting
- Parting-off
- Grinding
- Milling
#1. Turning Operation.
Turning is the operation of removing the excess material from the workpiece to produce a cylindrical surface to the desired length.
The job is held between the center or a chuck and rotating at a required speed. The tool moves in a longitudinal direction to give the feed toward the headstock with the proper depth of cut.
Different turning operations include:
1. Straight Turning.
Straight turning is the most common lathe operation. It features the removal of material from the outer surface of a rotating workpiece to reduce its diameter evenly, producing a smooth cylindrical shape.
The cutting tool moves parallel to the axis of the spinning workpiece, shaving off thin layers of material. This operation is essential for shaping shafts, rods, and pins with uniform diameters.
Tools:
- Single-point cutting tool (high-speed steel or carbide)
- Lathe chuck or centers for workpiece holding
Applications:
- Manufacturing machine shafts
- Producing metal rods and pins
- Creating cylindrical parts for automotive and machinery components
2. Taper Turning.
Taper turning creates a conical surface by gradually reducing the diameter of the workpiece along its length. The cutting tool moves at an angle to the axis of rotation, either by swivelling the compound rest or offsetting the tailstock.
This produces parts with a taper, such as tool holders or tapered shafts, which fit into matching components.
Tools:
- Single-point cutting tool with appropriate rake and relief angles
- Compound rest or adjustable tailstock
Applications:
- Tool holders and machine tapers
- Tapered pins and shafts are used in machinery assemblies
3. Contour Turning.
Contour turning shapes the workpiece into complex curved profiles rather than simple straight or tapered shapes.
The cutting tool follows a predefined path, controlled manually or by CNC programming, to form irregular or decorative curves. This operation is useful for making cams, pulleys with grooves, or ornamental parts.
Tools:
- Single-point cutting tools
- CNC lathe or skilled manual setup for tool guidance
Applications:
- Camshafts
- Decorative machine parts
- Custom curved profiles for special machinery
4. Step Turning.
Step turning produces a workpiece with distinct diameter sections separated by clear steps or shoulders. The cutting tool removes material at different depths along the length, creating a stepped profile.
This operation is important for parts like stepped shafts or pins that require multiple diameter changes.
Tools:
- Single-point cutting tool
- Lathe chuck or centres
Applications:
- Stepped shafts in engines or gearboxes
- Multi-diameter pins and connectors
5. Chamfer Turning.
Chamfer turning removes sharp edges by cutting a small, angled surface at the corner of the workpiece. This bevelled edge improves the safety of handling parts and prepares them for fitting or assembly. The tool is fed at an angle to the rotating workpiece, creating a smooth chamfer.
Tools:
- Single-point cutting tool set at the desired angle
Applications:
- Removing burrs and sharp edges
- Preparing parts for welding or assembly
- Improving the aesthetics and safety of finished parts
6. Form Turning.
Form turning uses a specially shaped cutting tool that matches the desired profile. The tool presses against the rotating workpiece to transfer its shape in one pass, producing complex profiles quickly. This operation is often used for decorative or functional shapes like grooves or ridges.
Tools:
- Formed a single-point cutting tool with a specific profile
Applications:
- Functional profiles such as gear teeth or ridges
- Decorative patterns on metal parts
#2. Facing.
Facing is a lathe operation used to create a smooth, flat surface on the end of a workpiece, ensuring it is perpendicular to the spindle axis. The workpiece is mounted in a chuck, and a cutting tool, typically a facing tool with a flat cutting edge, is positioned on the tool post.
The tool is fed perpendicularly across the rotating workpiece’s end, removing material in thin layers until the desired surface finish is achieved.
Facing is often the first step in machining, providing a reference surface for subsequent operations like turning or drilling, and it requires careful tool alignment to avoid uneven cuts.
#3. Chamfering.
It is the operation of getting a beveled surface at the edge of a cylindrical workpiece. This operation is done in the case of bolt ends and shaft ends.
Chamfering helps to avoid damage to the sharp edges and protects the operator from getting hurt during other operations. Chamfering on the bolt helps to screw the nut easily.
#4. Knurling.
Knurling is a lathe operation that creates a textured, crosshatched pattern on a workpiece’s surface to improve grip, often seen on tool handles or knobs.
A knurling tool, equipped with hardened rollers bearing the desired pattern, is pressed against the rotating workpiece, displacing material to form the texture.
The tool is fed slowly to ensure an even pattern, and the operation requires careful pressure control to avoid damaging the workpiece or tool. Knurling is typically performed at low spindle speeds, and operators must ensure the workpiece is securely mounted to withstand the applied force.
#5. Thread Cutting.
It is an important operation in the lathe to obtain the continuous ”helical grooves” or ” threads‘‘. When the threads or helical grooves are formed on the outer surface of the workpiece is called external thread cutting.
When the threads or helical grooves are formed on the inner surface of the workpiece is called internal thread cutting. The workpiece is rotating between the two centers i.e., the live center and the dead center of the lathe.
Here, the tool is moved longitudinally to obtain the required type of thread. When the tool is moved from the right to the left, we get the left-hand thread. Similarly, when the tool is moved from the left to the right, we get the right-hand thread.
Here, the motion of the carriage is provided by the lead screw. A pair of change gears drives the lead screw, and by rotating the handle, the depth of cut can be controlled.
#6. Filling.
It is the finishing operation performed after turning. This is done on a lathe to remove burrs, sharp corners, and feed marks on a workpiece, and also to bring it to its size by removing a very small amount of metal.
The operation consists of passing a flat single-cut file over the workpiece, which revolves at a high speed. The speed is usually twice that of turning.
#7. Polishing.
Polishing on a lathe is the process of refining and smoothing the surface of a rotating workpiece using abrasives, buffing tools, and polishing compounds. The primary goal is to remove machining marks, scratches, or imperfections and produce a smooth, reflective finish.
Polishing can be done on a wide range of materials, including metals such as steel, aluminum, and brass, as well as plastics and wood. The process is typically performed after machining operations like turning, facing, or threading to improve both the appearance and the functional performance of the part.
#8. Parting.
Parting, also known as cutting off, is the process of separating a finished workpiece from the raw material stock using a narrow parting tool. The tool is fed perpendicularly into the rotating workpiece at a steady rate, cutting a groove until the piece is fully severed.
Parting is often the final operation in machining a component and requires a rigid setup to prevent tool chatter or workpiece deflection.
Operators must use slow feed rates and adequate cutting fluid to reduce heat buildup and ensure a clean cut, taking care to stop the feed just before the piece separates to avoid damage.
#9. Grooving.
Grooving in machining refers to creating a narrow recessed feature (a groove) on a workpiece. The groove may be external, internal, or on the face of the part, and is typically used to house sealing rings, allow for part assembly, or relieve stress.
Unlike turning, which removes material across a wider surface, grooving uses a specially shaped tool to plunge into a specific point, removing material in a localized zone. It is typically rotational and limited to cylindrical parts.
#10. Forming.
It is the process of turning a convex, concave, or irregular shape. Form-turning may be accomplished by the following method:
- Using a forming tool.
- Combining cross and longitudinal feed.
- Tracing or copying a template.
Forming tools are not supposed to remove much of the material and are used mainly for finishing formed surfaces.
Generally, two types of forming tools are used: straight and circular. The straight type is used for wider surfaces and the circular type for narrow surfaces.
#11. Drilling.
Drilling on a lathe involves creating a cylindrical hole in a workpiece using a twist drill bit held in the tailstock or a chuck. The workpiece rotates in the headstock chuck, while the drill bit is advanced into it, either manually or via the tailstock quill.
This operation is used to create holes for bolts, dowels, or as a starting point for boring. Proper alignment of the drill bit with the workpiece’s center is crucial to avoid off-center holes, and operators must use appropriate cutting fluid and speeds to prevent overheating and ensure clean, accurate holes.
#12. Reaming.
Reaming is the operation of finishing and sizing a hole that has already drilled or bored. The tool used is called the reamer, which has multi-plate cutting edges.
The reamer is held on the tailstock spindle, either directly or through a drill chuck, and is held stationary while the work is revolved at a very slow speed.
#13. Boring.
Boring is the operation of enlarging the hole that is already drilled, punched, or forged. It cannot produce a hole.
Boring is similar to the external turning operation and can be performed in a lathe. In this operation, the workpiece is revolved in a chuck or a faceplate, and the tools that are fitted to the tool post are fed into the work.
It consists of a boring bar having a single-point cutting tool that enlarges the hole. It also corrects the out-of-roundness of a hole. This method is adopted for boring small-sized work only. The speed of this process is slow.
#14. Counterboring.
Counterboring is the operation of enlarging the end of the hole by a certain distance. It is similar to shoulder work in external turning.
The operation is similar to boring and plain boring tools, or a counterbore may be used. The tool is called a counterbore. The speed is slightly less than drilling.
#15. Taper Boring.
The principle of turning a tapered hole is similar to the external taper turning operation and is completed by rotating the work on a chuck or a faceplate. The feeding tool is at an angle to the axis of rotation of the workpiece.
A boring tool is mounted on the tool post, and by swiveling the compound slide to the desired angle, a short taper hole is machined by hand feeding.
#16. Tapping.
Tapping is the operation of cutting internal threads of small diameter using a multipoint cutting tool called the tap.
In a lathe, the work is mounted on a chuck or a faceplate and revolved at a very slow speed. A tap of the required size held on a special fixture is mounted on the tailstock spindle.
#17. Undercutting.
Undercutting is similar to a grooving operation when performed inside a hole. It is the process of boring a groove or a large hole at a fixed distance from the end of a hole.
This is similar to the boring operation, except that a square nose parting is used. Undercutting is done at the end of an internal thread or a counterbore to provide clearance for the tool or any part.
#18. Milling in the lathe machine operations.
Milling is the operation of removing metal by feeding the work against a rotating cutter having multiple cutting edges.
For cutting keyways or grooves, the work is supported on the cross-slide by a special attachment and fed against a rotating milling cutter held by a chuck. The depth of cut is given by the vertical adjustment of the work provided by the attachment.
The depth of cut is given by the vertical adjustment of the work provided by the attachment. The feeding movement is provided by the carriage, and the vertical movement of the cutter is arranged in the attachment.
#19. Grinding.
Grinding is the operation of removing metal in the form of minute chips by feeding the work against a rotating abrasive wheel known as the grinding wheel.
Both the internal and external surfaces of a workpiece may be ground by using a special attachment mounted on the cross slide.
For the grinding of the external surface, the work may revolve between centers or on a chuck. For internal grinding, the work must be revolved around a chuck or faceplate.
The feeding is done by the carriage, and the depth of cut is provided by the cross slide. Grinding is performed in a lathe for finishing a job, sharpening a cutter, or sizing a workpiece after it has been hardened.
FAQs.
Q: What is a lathe machine?
A lathe machine is a tool that precisely cuts, shapes, and drills a workpiece by rotating it around its axis.
Q: What are the advantages of a lathe machine?
A lathe machine can finish machining operations fast and efficiently, especially when using automated procedures. A lathe machine can be an affordable way to produce custom parts in small-scale production.
Q: What are the different types of lathe operations?
The most frequent lathe operations include turning, facing, grooving, parting, threading, drilling, boring, knurling, and tapping.
Q: What is the difference between turning and facing on a lathe?
The facing operation is used to shorten the length of a material. The turning action reduces the diameter of the material.