Parts of a Lathe

S.GunabalanAssociate ProfessorMechanical Engineering DepartmentBharathiyar College of Engineering & TechnologyKaraikal - 609 609.e-Mail : gunabalans@yahoo.com

Parts of a Lathe

Headstock

Holds lathe spindle and gears

Chuck is fitted to spindle

Spindle is hollow for long bars

CarriageMoves the cutting tool along bed between tailstock and headstock

Carriage

4-Way Tool Post. Mounts up to four cutting tools at a time and rotates to index each of them to the workpiece as needed.

Compound Rest Hand wheel.

Moves the tool relative to the workpiece at the set angle. The attached indirect graduated dial has 0.001" (0.02mm) increments, with one full revolution equaling 0.100" (2.54mm) of travel.

Carriage HandwheelMoves the carriage longitudinally along the bedway. The attached graduated dial has 0.020“ increments with one full revolution equaling 0.100" of travel.

Carriage

Carriage Lock.

Secures the carriage in place on the bedway for additional rigidity when the carriage should not move during the operation.

Saddle. Supports the cross slide, compound rest, and tool post over the bedway.

CarriageCompound Rest

Angle Scale. Displays the angle of the compound rest

left or right from the spindle center line in

increments of one degree.

Feed Selection Lever. Selects either the carriage

or cross slide for power feed operations. When in

the neutral (middle) position, power feed is

disabled. This lever works in conjunction with the

feed knob.

Carriage

Thread Chasing Dial Assembly. Displays the correct position to engage the half nut when inch threading.

Half Nut Lever. Engages/disengages the half nut with the longitudinal lead screw for threading operations

CarriageFeed Knob.

When tightened, engages either the carriage or cross slide for power feeding. Conversely, when

loosened, disengages power feed. If the feed selection lever is in the neutral position or the

half-nut is engaged, the feed knob has no effect.

Half Nut Lever. Engages/disengages the half nut with the longitudinal lead screw for threading operations

CarriageFeed Knob.

When tightened, engages either the carriage or cross slide for power feeding. Conversely, when

loosened, disengages power feed. If the feed selection lever is in the neutral position or the

half-nut is engaged, the feed knob has no effect.

Cross Slide Handwheel. Moves the cross slide toward or away from the spindle centerline.

Cross Slide Handwheel. Moves the cross slide toward or away from the spindle centerline.

Compound Rest Angle Scale. Displays the angle of the compound rest left or right from the spindle centerline in increments of one degree.

Compound Rest Hand wheel. Moves the tool relative to the workpiece at the set angle.

LATHE BED

Made from Gray Cast Iron Accurately machined

slideways Slideways guide carriage

& tailstock Headstock on upper end

of the lathe bed

Lathe parts

• Tailstock Can be moved along

slideways Can be clamped in any location Inside tapered to hold drill chuck

Lathe parts

• Cross Slide Fitted on the Saddle Moves cutting tool at

right angles to lathe bed

Lathe parts

• Feed shaft Used to move the

Carriage automatically

• Lead screw Used when screw

cutting on the lathe

Lathe Parts

• Three Jaw Chuck Self centring Holds round and

hexagonal work 3 jaws are connected Jaws are stamped 1,2 & 3

and fitted in order Chuck key used to open

Lathe parts

• Toolpost Fitted on top slide and

carries the cutting tool or the cutting tool holder

Can adjust the height on some types

Can carry 4 different tool holders

Lathe parts

• Tool holders Used for holding

cutting tool bits Available in Right

hand, left hand and straight

• Cutting Tools Can be High Speed

Steel held in tool holders

Can be also Ceramic (Tungsten carbide) bits held directly in toolpost