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Welcome

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u

YsTYPES OF

screw THREAD &

THEIR ELEMENTS

Ys INTRODUCTION

DEFINITION AND MAIN

ELEMENTS OF THREAD

USES OF THREADS

CLASSIFICATION OF

THREADS

SCREW THREADS

YsSCREW THREADS

YsINTRODUCTION

PLAY AN IMPORTANT ROLE IN

ENGINEERING INDUSTRY

EASIEST FASTENERS

SCREW THREADS

YsDEFINITION

A THREAD IS A HELICAL RIDGE OF UNIFORM SECTION THAT LIES ON INSIDE OR OUTSIDE OF A CYLINDER OR CONE

CUTTING GROOVES OF EQUAL LENGTH AND EQUAL DEPTH ON EXTERNAL OR INTERNAL SURFACE OF A CYLINDRICAL OR CONE SHAPED JOB ARE CALLED THREAD CUTTING

SCREW THREADS

Ys ELEMENTS

MAJOR DIAMETER

MINOR DIAMETER

PITCH DIAMETER

PITCH

SCREW THREADS

YsPITCH ROOT CREST

DEPTH

MINOR DIA

PITCH DIA

MAJOR

DIA

THREAD ANGLE

SCREW THREADS

YsSCREW THREADS

Angle CrestFlank Pitch Point

Root Thread Depth Pitch Base of Thread

ELEMENTS OF THREAD

MINOR DIA

PITCH DIA

MAJOR

DIA

Center Axis Depth

Ys ROOT

CREST

FLANK

THREAD ANGLE

ELEMENTS

SCREW THREADS

YsPITCH ROOT CREST

DEPTH

MINOR DIA

PITCH DIA

MAJOR

DIA

THREAD ANGLE

SCREW THREADS

YsELEMENTS OF SCREW THREADS

MAJOR DIAMETER

CREST OR OUTSIDE DIAMETER OF

EXTERNAL THREAD

ROOT DIAMETER OF INTERNAL

THREAD

MAJOR DIAMETER = CORE

DIAMETER + (2 X DEPTH OF THREAD)

YsPITCH ROOT CREST

DEPTH

MINOR DIA

PITCH DIA

MAJOR

DIA

THREAD ANGLE

SCREW THREADS

YsELEMENTS OF SCREW THREADS

MINOR DIAMETER

CORE OR ROOT DIAMETER OF

EXTERNAL THREAD

CREST DIAMETER OF INTERNAL

THREAD

MINOR DIAMETER =

MAJOR DIAMETER – 2 DEPTH

YsSCREW THREADS

Angle CrestFlank Pitch Point

Root Thread Depth Pitch Base of Thread

ELEMENTS OF THREAD

MINOR DIA

PITCH DIA

MAJOR

DIA

Center Axis Depth

YsELEMENTS OF SCREW THREADS

PITCH DIAMETER

DIAMETER OF CENTERS OF TWO

OPPOSITE THREADS

ASSUMED DIAMETER

PASSES THROUGH CENTRE OF

THREADS

PD = MAJOR DIAMETER – DEPTH

YsSCREW THREADS

Angle CrestFlank Pitch Point

Root Thread Depth Pitch Base of Thread

ELEMENTS OF THREAD

MINOR DIA

PITCH DIA

MAJOR

DIA

Center Axis Depth

YsELEMENTS OF SCREW THREADS

PITCH

DISTANCE BETWEEN CORRESPONDING

POINTS OF TWO ADJACENT THREADS

MEASURED PARALLEL TO AXIS

PITCH = 1 / TPI

YsPITCH ROOT CREST

DEPTH

MINOR DIA

PITCH DIA

MAJOR

DIA

THREAD ANGLE

SCREW THREADS

YsELEMENTS OF SCREW THREADS

ROOT BOTTOM PORTION OF THE THREAD

WHERE BOTH SIDES MEET

CREST TOP PORTION OF THE THREAD WHERE

BOTH SIDES MEET

FLANK STRAIGHT SIDES, WHICH CONNECT THE

CREST WITH THE ROOT

YsPITCH ROOT CREST

DEPTH

MINOR DIA

PITCH DIA

MAJOR

DIA

THREAD ANGLE

SCREW THREADS

YsELEMENTS OF SCREW THREADS

THREAD ANGLE ANGLE AT WHICH BOTH SIDES OF THE

THREAD MEET

AXIS OF A SCREW LONGITUDINAL CENTERLINE THROUGH

A SCREW

BASE OF THE THREAD BOTTOM SECTION OF THE THREAD

GREATEST SECTION BETWEEN THE TWO ADJACENT ROOTS

YsPITCH ROOT CREST

DEPTH

MINOR DIA

PITCH DIA

MAJOR

DIA

THREAD ANGLE

SCREW THREADS

Ys DEPTH OF THREAD

DISTANCE FROM CREST TO ROOT MEASURED VERTICALLY

LEAD DISTANCE TRAVELED BY A NUT IN

ONE COMPLETE REVOLUTION

SINGLE START THREADS : LEAD = PITCH

MULTI START THREADS : LEAD = PITCH X NUMBER OF STARTS

SCREW THREADS

YsPITCH ROOT CREST

DEPTH

MINOR DIA

PITCH DIA

MAJOR

DIA

THREAD ANGLE

SCREW THREADS

Ys THREADS PER INCH

NUMBER OF THREADS IN ONE INCH

LENGTH OF SCREW. IT IS ABBREVIATED AS

TPI.

THICKNESS OF THREADS

DISTANCE BETWEEN THE ADJACENT

SIDES OF THE THREADS MEASURED

ALONG THE PITCH LINE

SCREW THREADS

YsPITCH ROOT CREST

DEPTH

MINOR DIA

PITCH DIA

MAJOR

DIA

THREAD ANGLE

SCREW THREADS

Ys DEPTH OF ENGAGEMENT

DEPTH OF THE THREAD CONTACT OF

TWO MATING PARTS MEASURED

RADIALLY

LENGTH OF ENGAGEMENT

LENGTH OF CONTACT BETWEEN TWO

MATING PARTS MEASURED AXIALLY.

SCREW THREADS

Ys CLASSIFICATION

ACCORDING TO POSITION

SHAPE AND WORK

DIRECTION

NUMBER OF STARTS

SCREW THREADS

YsACCORDING TO POSITION

EXTERNAL THREADS

INTERNAL THREADS

SCREW THREADS

YsSCREW THREADS

EXTERNAL AND INTERNAL THREAD CUTTING

Ys ACCORDING TO SHAPE & WORK

V – THREADS

SQUARE THREADS

ACME THREADS

BUTTRESS THREADS

WORM THREADS

SCREW THREADS

YsV-THREADS

YsSQUARE THREADS

FOLLOWING ANGLE

LEADING ANGLE

YsWORM THREADS

YsSCREW THREADS

WORM AND WORM GEAR

YsACME THREADS

PITCH29 DEG

DEPTH

PITCH

SQUARE THREADS

YsBUTTRESS THREADS

CREST

PITCH

Ys ACCORDING TO DIRECTION

RIGHT HAND THREADS

LEFT HAND THREADS

SCREW THREADS

Ys ACCORDING TO NUMBER OF STARTS

SINGLE START THREADS

MULTI START THREADS

SCREW THREADS

YsSQUARE THREADS

FOLLOWING ANGLE

LEADING ANGLE

Ys USED IN LIFTING WEIGHT, VICE

SPINDLES, PRESS MACHINE SPINDLE,

POWER TRANSMISSION AND SCREW

JACK ETC

ANGLE = 90°

DEPTH = 0.5 X PITCH

CREST AND ROOT WIDTH = 0.5 X PITCH

SQUARE THREADS

YsSCREW THREADS

Taper

SQUARE THREADS

FOUR JAW CHUCK

THREE JAW CHUCK

YsSCREW THREADS

Frame

Ram

Base

Screw Thread

ADJUSTABLE BED PRESS

SQUARE THREADS

YsACME THREADS

PITCH29 DEG

DEPTH

PITCH

SQUARE THREADS

Ys ANGLE = 290

DEPTH = 0.5 X P + 0.01 INCH

FLAT AT BOTTOM =.3707X P-.0052

FLAT AT TOP =.3707X P

ACME THREADS

Ys USED FOR POWER TRANSMISSION

USED WHERE ENGAGEMENT WITH A

HALF NUT IS REQUIRED AS IN LATHE

ANGLE = 290

DEPTH = 0.5 X P + 0.001 INCH

ACME THREADS

YsSCREW THREADS

LATHE MACHINE

leLEAD SCREW

YsBUTTRESS THREADS

CREST

PITCH

Ys TOOTH SHAPE TRIANGULAR

450 AT ONE SIDE & 900 AT ANOTHER

SIDE

DEPTH = 0.75 X P

WIDTH AT CREST & ROOT = 0.125 X P

BUTTRESS THREADS

Ys ROUNDED SQUARE THREAD

SUITABLE FOR ROUGH AND HEAVY WORK

COUPLING RODS OF RAILWAY ROLLING STOCK

ANGLE = 900

DEPTH = 0.5 X P

RADIUS = 0.25 X P

KNUCKLE THREADS

YsSCREW THREADS

COUPLING RODS OF RAILWAY ROLLING STOCK

Ys

CONCLUSION

YsAny

Question please?

YsSCREW THREADS

THANK YOU

YsSCREW THREADS

YsSCREW THREADS

YsSCREW THREADS

YsSCREW THREADS

YsSCREW THREADS

YsSCREW THREADS

YsSCREW THREADS

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