Threaded Fasteners
description
Transcript of Threaded Fasteners
![Page 1: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/1.jpg)
Threaded FastenersChapter 11
![Page 2: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/2.jpg)
TOPICS
Introduction
Thread terminology
Thread drawing and dimensioning
Threaded fastener
![Page 3: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/3.jpg)
Introduction
![Page 4: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/4.jpg)
FASTENING TYPE
1. Permanent
WeldingWelding GluingGluing RivetingRiveting
![Page 5: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/5.jpg)
FASTENING TYPE
2.1 Threaded fastener
- bolts
- studs
- screws
2. Temporary
2.2 Non-threaded fastener
- keys
- pin
key
![Page 6: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/6.jpg)
THREAD APPLICATION
1. To hold parts together.
2. To move part(s) relative to others.
Part A Part B
Part C
![Page 7: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/7.jpg)
THREAD APPLICATION
1. To hold parts together.
2. To move part(s) relative to others.
Wood working vise Palm fruit pressing machine
![Page 8: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/8.jpg)
Thread Terminology
![Page 9: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/9.jpg)
External (male)thread
Internal (female)thread
THREAD TERMINOLOGY
A thread cut on the outside of
a cylindrical body.
A thread cut on the inside of
a cylindrical body.
Internal thread
External thread
![Page 10: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/10.jpg)
Right-handthread
Thread that will assemble when
turned clockwise.
Left-handthread
Thread that will assemble when
turned counter-clockwise.
THREAD TERMINOLOGY
Turnbuckle use RH and LH thread at each end to double displacement.
![Page 11: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/11.jpg)
Crest
Root
Thread angle
THREAD TERMINOLOGY
The peak edge of a thread.
The bottom of the thread cut intoa cylindrical body.
The angle between threads faces.
Internal ThreadExternal Thread
CrestRoot
Thread angle
CrestRoot
![Page 12: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/12.jpg)
Major diameterThe largest diameter on
an internal or external thread.
Minor diameterThe smallest diameter on
an internal or external thread.
Internal ThreadExternal ThreadM
inor
dia
.
Ma
jor
dia
.
THREAD TERMINOLOGY
Min
or d
ia.
Ma
jor
dia
.
![Page 13: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/13.jpg)
PitchThe distance between crests of
threads.
Lead The distance a screw will advance
when turned 360o.
THREAD TERMINOLOGY
Internal ThreadExternal Thread
PitchPitch
![Page 14: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/14.jpg)
Form is the profile shape of thethread.
Thread Form
THREAD TERMINOLOGY
Example :
“knuckle thread form”
![Page 15: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/15.jpg)
EXTERNAL THREAD CUTTING
Tools Operation
Threading Die
Die stock
![Page 16: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/16.jpg)
Twist drill
Tools
Tap
Tap wrench
Operation
INTERNAL THREAD CUTTING
![Page 17: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/17.jpg)
COMPARISON OF THREAD CUTTING
External Thread Internal Thread
Major Dia.
Minor Dia.
![Page 18: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/18.jpg)
Thread Drawing
![Page 19: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/19.jpg)
1. 1. DetailedDetailed representation representation
2. 2. SchematicSchematic representation representation
3. 3. Simplified Simplified representationrepresentation
THREAD REPRESENTATION
![Page 20: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/20.jpg)
External thread Internal thread
DETAILED REPRESENTATION
60oPitch
Use slanting lines to represent crest and root.
Roots and crest are drawn in sharp Vs.
Thread runout
![Page 21: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/21.jpg)
SCHEMATIC REPRESENTATION
External thread
Pitch Crest (thin line)
Root (thick line)
Use alternate long and short lines for representing
crests and roots of the thread, respectively.
Internal thread
![Page 22: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/22.jpg)
SIMPLIFIED REPRESENTATION
External thread Internal thread
Use thick continuous lines for representing crest
and thin continuous lines for representing root of
the thread, respectively.
Pitch/2
Root
Crest
Thread runout
![Page 23: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/23.jpg)
SIMPLIFIED REPRESENTATION
External thread Internal thread
Sectional view
Use thick continuous lines for representing crest
and thin continuous lines for representing root of
the thread, respectively.
![Page 24: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/24.jpg)
ISO (METRIC) THREAD
Externalthread
Internalthread
Center of thread assembly
60o
Pitch, P
P/4
P/8
Thread assemble occurs if and only if both (internal & external)
thread have an equal nominal size (or diameter) and pitch.
![Page 25: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/25.jpg)
Nominal
size
Major diameter
Pitch Minor diameter
Tap drill size
M6 6.00 1.00 4.92 5.00
M8 8.00 1.25 6.65 6.75
M10 10.00 1.50 8.38 8.50
M12 12.00 1.75 10.11 10.00
METRIC COARSE THREAD
Minor diameter = Major diameter – Pitch
Minor diameter ≈ Tap drill size
[Table 9.1]
Metric thread
In thread drawing, the following relationship is used.
![Page 26: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/26.jpg)
Nominal
size
Major diameter
Pitch Minor diameter
Tap drill size
M8 8.000.75 7.188 7.25
1.00 6.917 7.00
M10 10.00
0.75 9.188 9.25
1.00 8.917 9.00
1.25 8.647 8.75
METRIC FINE THREAD[Table 9.2]
Minor diameter = Major diameter – Pitch
Minor diameter ≈ Tap drill size
In thread drawing, the following relationship is used.
![Page 27: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/27.jpg)
Thread Length
DRAWING STEPS OFEXTERNAL THREAD
Startingposition
Drawthreadaxis M
ajo
r d
ia.
Min
or d
ia.
Draw45o Chamfer
Draw line making30o with thread axis
Draw a circle thatrepresents a crest.
Draw an arc thatrepresents a root.
![Page 28: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/28.jpg)
Internal Thread
1. Through threaded hole
DRAWING STEPS OFTHREADED HOLE
Drawthreadaxis M
ajo
r d
ia.
Min
or d
ia.
Draw a root
Draw a crestSectional view
Draw a circle thatrepresents a crest.
Draw an arc thatrepresents a root.
root
crest
Section lines are drawn into the crest of a thread.
![Page 29: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/29.jpg)
Min
or d
ia.
DRAWING STEPS OFTHREADED HOLE
2. Blinded threaded hole
Drawthreadaxis M
ajo
r d
ia.
Hole depth
Thread depthDraw a circle thatrepresents a crest.
Draw an arc thatrepresents a root.
![Page 30: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/30.jpg)
DRAWING STEPS OFTHREADED HOLE
2. Blinded threaded holeSectional view
![Page 31: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/31.jpg)
DIMENSIONING EXTERNAL THREAD
M10 ×1.5 ×1.0 Fine thread
Coarse thread
xxThreadlength
Use local note to specify :- thread form, nominal size, pitch (if it is a fine thread)
Use typical method to specify :- thread length.
![Page 32: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/32.jpg)
3. Thread form
4. Nominal size
5. Pitch
1. Tap drill size
2. Drill depth
6. Thread depth
8.50 Drill, 20 Deep,
M10 Tapped, 15 Deep
DIMENSIONING THREADED HOLE
Use local note tospecify
![Page 33: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/33.jpg)
Threaded Fastener
![Page 34: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/34.jpg)
BOLT : Terminology
Bolt is a threaded cylinder with a head.
Hexagonal head
bolt and nutHead
thickness
Thread length
Length
Width across flat
Dimensions of bolt’s head are
listed in table 9.4.
![Page 35: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/35.jpg)
Drawboltaxis
Draw anend view
of the head
B
Startingposition
H
Draw abolt head
B/2 B/2
30o
Length
Thread Length
Maj
or
Draw body of a bolt
BOLT : Drawing steps
![Page 36: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/36.jpg)
NUT : Drawing steps
Draw an end viewof the nut
BH
B/2 B/2
Dimensions of the nut are given in Table 9.14.
Dash lines represent
a threaded hole are
omitted for clarity.
![Page 37: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/37.jpg)
1. Insert a bolt intoa clearance hole
2. Insert a washer.
3. Screw a nut.
BOLT : Application
![Page 38: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/38.jpg)
Let’ s think together… What do you think about the following suggestions for
design improvement?
(B) Use shorter bolt with the same thread length.(B) Use shorter bolt with the same thread length.
CorrectCorrect
(C) Reduce the thread length.(C) Reduce the thread length.
InappropriateInappropriate WrongWrong
(D) Add washer or nut.(D) Add washer or nut.
(A) Nothing have to be changed.(A) Nothing have to be changed.
![Page 39: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/39.jpg)
Let’ s think together… What do you think about the following suggestions for
design improvement?
(B) Use a bolt of this length but has a longer thread length.(B) Use a bolt of this length but has a longer thread length.
(C) Use a longer bolt with the same thread length.(C) Use a longer bolt with the same thread length.
(D) Add washer.(D) Add washer.
(A) Nothing have to be changed.(A) Nothing have to be changed.
CorrectCorrect InappropriateInappropriate WrongWrong
![Page 40: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/40.jpg)
Let’ s think together… What do you think about the following suggestions for
design improvement ?
(B) Use a bolt of this length but has a shorter thread length.(B) Use a bolt of this length but has a shorter thread length.
(C) Use a longer bolt with the same thread length.(C) Use a longer bolt with the same thread length.
(D) Add washer.(D) Add washer.
(A) Nothing have to be changed.(A) Nothing have to be changed.
CorrectCorrect InappropriateInappropriate WrongWrong
![Page 41: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/41.jpg)
Let’ s think together… What do you think about the following suggestions for
design improvement?
(A) Use a bolt of this length but has a shorter thread length.(A) Use a bolt of this length but has a shorter thread length.
(B) Use a longer bolt with the same thread length.(B) Use a longer bolt with the same thread length.
(C) Use a longer bolt by increasing a thread length(C) Use a longer bolt by increasing a thread length
(D) Remove washer.(D) Remove washer.
CorrectCorrect InappropriateInappropriate WrongWrong
![Page 42: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/42.jpg)
Let’ s think together… What do you think about the following suggestions for
design improvement ?
(A) Increase the bolt diameter.(A) Increase the bolt diameter.
(B) Use washer with larger outside diameter.(B) Use washer with larger outside diameter.
(C) Reduce the hole diameter.(C) Reduce the hole diameter.
(D) Add washer at bolt head.(D) Add washer at bolt head.
CorrectCorrect InappropriateInappropriate WrongWrong
![Page 43: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/43.jpg)
Let’ s think together… What do you think about the following suggestions for
design improvement ?
(B) Use a bolt with shorter thread length.(B) Use a bolt with shorter thread length.
(C) Add washer.(C) Add washer.
(D) Increase drill and thread depths.(D) Increase drill and thread depths.
(A) Nothing have to be changed.(A) Nothing have to be changed.
CorrectCorrect InappropriateInappropriate WrongWrong
![Page 44: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/44.jpg)
Let’ s think together… What do you think about the following suggestions for
design improvement ?
(A) Nothing have to be changed.(A) Nothing have to be changed.
(B) Use a bolt with slightly longer thread length.(B) Use a bolt with slightly longer thread length.
CorrectCorrect InappropriateInappropriate WrongWrong
![Page 45: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/45.jpg)
Stud is a headless bolt, threaded at both ends.
STUD : Terminology
Thread length
Length
Thread length
Drawing
representation
![Page 46: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/46.jpg)
Ma
jor
STUD : Drawing steps
Drawstudaxis M
inor
Startingposition
Stud Length
Thread Length Thread Length
Draw45o Chamfer
Draw45o Chamfer
Draw line making30o with axis
![Page 47: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/47.jpg)
STUD : Application
1. Drill a hole.
3. Screw a stud.
4. Place the part to be fastened.
5. Insert washer and fastened a nut.
2. Tap a hole.
![Page 48: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/48.jpg)
Let’ s think together… What is the mistake in the following use of stud ?
![Page 49: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/49.jpg)
Let’ s think together… What is the mistake in the following use of stud ?
![Page 50: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/50.jpg)
Cap screw is similar to bolt, but has a longer thread
than a bolt.
CAP SCREW : Terminology
![Page 51: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/51.jpg)
CAP SCREW : Counterbore hole
x drill,y C’bore,
z deep
x drill,w deep,y C’bore,z deep
z
![Page 52: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/52.jpg)
x drill,CSK to y
CAP SCREW : Countersink hole
x drill, w deep,CSK to y
yDraw 90o
![Page 53: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/53.jpg)
SET SCREW : Terminology
Set screw is a threaded cylinder used to prevent
rotation or movement between parts.
![Page 54: Threaded Fasteners](https://reader033.fdocuments.net/reader033/viewer/2022061612/5681530e550346895dc1318f/html5/thumbnails/54.jpg)
SET SCREW : Application