Construction of Lathe: Bed, Tailstock, Carriage, Saddle, Cross slide, Compound slide ~ MECHTECH GURU

Construction of Lathe: Bed, Tailstock, Carriage, Saddle, Cross slide, Compound slide

Construction of Lathe

Construction of Lathe: Bed, Tailstock, Carriage, Saddle, Cross slide, Compound slide
Construction of Lathe
Following are the principal parts of center lathe:
1.       Bed                          4.  Carriage
2.       Headstock                5.  Feed mechanism
3.       Tailstock                  6.  Screw cutting mechanism

            The Bed

·        The lathe bed forms the base of the machine. The headstock and the tailstock are mounted on lathe bed and the carriage rests over the lathe bed.
·        For accurate machining work, must satisfy the following conditions:
Ø It should be sufficiently rigid to prevent deflection under tremendous cutting pressure transmitted through the tool-post and carriage to the lathe bed.
Ø It must be massive with sufficient depth and width to absorb vibration.
Ø It must resist the twisting stress set up due to the resultant of two forces- the downward cutting force on the tool and the force tending to move the tool away from the workpiece in a horizontal direction.
Ø The bed should be seasoned naturally to avoid distortion or warp that may develop when it is cooled after the bed is cast.
·        On the top of the bed there are two sets of slides or guideways.

                   A.     Outer guideways
                   B.     Inner guideways
·        Outer guideways provide bearing and sliding surfaces for the carriage, and the Inner guideways for the tailstock.
1 – Inverted – V bedways, 2 – Flat bedways, 3 – Rack, 4 – Box section,
 5 – flat bedways for saddle

                                                            1  Diagonal rib, 2  Bedways


·    The headstock is permanently mounted on the inner ways at the left side of the lathe bed. It provides the rotating of workpiece at multiple speeds.
·    The headstock spindle is shown in Fig is made of carbon or nickel chrome steel. This is usually of a large diameter to avoid bending and it should be perfectly aligned for accurate machining.
·    The long bar or work holding devices to pass through, the headstock spindle is made hollow.
·    There are common two types of spindle noses: Threaded nose which carries the chuck, driving plate and face plate, and Flanged nose which enable them to be directly attached. The lathe most commonly used has a threaded spindle nose.



·    The tailstock is located on the inner ways at right hand end of the bed.
·    Main uses of tailstock:
A.     It supports the other end of workpiece when it is being machined between two centers.
B.     It holds a tool for performing operations like drilling, reaming, tapping etc.
·    The tailstock may be adjusted as length of workpiece is different or vary by clamping of bolts.
·    Upper casting of body can be moved away from the operator by means of offseting the tailstock for taper turning.
·    The body is bored to act as the barrel which carries tailstock spindle which can be moves in and out of barrel by means of handwheel.
·    The front of the spindle has taper hole into which dead center or tools are mounted.
·    Other features of tailstock are graduated spindles and micrometer dials on handwheel for accurate length setting.


·    The carriage of lathe has several parts that to support, move and control the cutting tool.
·    It consists of the following parts:
A.       Saddle                    D.  Tool post
B.       Cross slide               E.  Apron
C.      Compound slide

A.     Saddle

·    The saddle is an H shaped casting that fits over the bed and slides along the ways.
·    It carries the cross slide and tool post. Some attachments are generally provided for locking the saddle to prevent any movement when surfacing operations are carried out.

B.      Cross slide

·        Cross slide is a casting and attached to the saddle and carries tool post and compound slide.
·        Cross slide is attached to the saddle at right angles to the center axis of the lathe.
·        When taper turning attachment is used, the binder screw is opened to disconnect the cross slide from the cross feed screw.
·        Micrometer dials may be fitted on cross slide so that a known amount of feed can be applied.

C.      Compound slide

·    The compound rest or compound slide is mounted on the top of cross slide and has a circular base in degrees.
It is used for obtaining angular cuts and short tapers.
·    By loosening of two set screws, rest may be swiveled to any angle within circle.
·    There is no power feed to the compound rest and it is hand operated.
·    The compound slide handle is also equipped with micrometer dial to determining the depth of cut.


     1 Tool post screw, 2 Tool post, 3 Rocker, 4 Tool, 5 Concave ring, 6 Compound rest swivel base, 7 Cross feed screw, 8 Binder screw, 9 Cross slide, 10 Cross slide nut, 11 Saddle, 12 Pinion on Cross feed screw for automatic feed, 13 Cross slide hand wheel, 14 Compound slide hand wheel, 15 Compoundslide feed screw, 16 Compound rest, 17 – Compound slide nut.

A.     Tool post
·        This is located on the top of compound rest to hold the tool and able to be adjusted to a convenient working position.
·        The type and mounting of tool post depends on the class of work for which it is to be used.
·        Following are the common types of tool post:
1.         Single screw tool post         3.    Open side tool post
2.         Four bolt tool post             4.    Four way tool post

1.    Single screw tool post
·        This tool post consists of a round bar with slotted hole in the center for fixing the tool by means of set screw.
·        The height can be adjusted by tightening of rocker and clamping it in bye set screw.
·        The tool post is not rigid enough for heavy work as only one clamping screw is used to clamp the tool. The tool post can be swiveled about the vertical axis.



             1 – Toolpost screw, 2 – Toolpost body, 3 – Tool,
 4 – Convex rocker,
 5 – Concave ring  Single screw tool post

Tool Post
Tool Post


Next Post »


Click here for comments
March 23, 2022 at 2:52 PM ×

Most of educational information over different kinds of blogs do not such supportive as supportive all the points of this blog. You need not to find any other platform to verify the data stated here. Best Online Glass Railing Clamp