GD&T
31
Department of Mechanical Engineering and Mechanics Fundamentals of Computer Aided Design Geometrical Dimensioning & Tolerancing (GD&T) MEM 201
description
mechanical gd&t
Transcript of GD&T
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Fund
amen
tals
of C
ompu
ter A
ided
Des
ign
Geo
met
rical
Dim
ensi
onin
g &
To
lera
ncin
g (G
D&
T)
MEM
201
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Toda
y�s
Obj
ectiv
es�
..
�To
lera
nces
and
why
do
we
need
them
.�
Diff
eren
t typ
es o
f tol
eran
ces.
�To
lear
n ho
w to
effe
ctiv
ely
tole
ranc
e pa
rts
in e
ngin
eerin
g dr
awin
gs.
�A
llow
ance
/Cle
aran
ce
�E
xpre
ssin
g to
lera
nces
in A
utoC
AD.
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
ing
�D
efin
ition
: �A
llow
ance
for a
spe
cific
var
iatio
n in
the
size
and
ge
omet
ry o
f par
t.�
�W
hy is
it n
eede
d: N
o on
e or
thin
g is
per
fect
!
�H
ence
, eng
inee
rs h
ave
com
e up
with
a w
ay to
mak
e th
ings
cl
ose
to p
erfe
ct b
y sp
ecify
ing
Tole
ranc
es!
�Si
nce
varia
tion
from
the
draw
ing
is in
evita
ble
the
acce
ptab
le d
egre
e of
var
iatio
n m
ust b
e sp
ecifi
ed.
�La
rge
varia
tion
may
affe
ct th
e fu
nctio
nalit
yof
the
part
�Sm
all v
aria
tion
will
effe
ct th
e co
st o
f the
par
t�
requ
ires
prec
ise
man
ufac
turin
g.�
requ
ires
insp
ectio
n an
d th
e re
ject
ion
of p
arts
.
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Whe
n do
es T
oler
ance
s be
com
e im
porta
nt
�A
ssem
blie
s:
Parts
w
ill of
ten
not
fit
toge
ther
if
thei
r di
men
sion
s do
not
fall
with
in a
cer
tain
rang
e of
val
ues.
�In
terc
hang
eabi
lity:
If a
repl
acem
ent p
art i
s us
ed it
mus
t be
a du
plic
ate
of t
he o
rigin
al p
art
with
in c
erta
in l
imits
of
devi
atio
n.�
The
rela
tions
hip
betw
een
func
tiona
lity
and
size
or
shap
e of
an
obje
ct v
arie
s fro
m p
art t
o pa
rt. Tole
ranc
es a
re im
port
ant h
ere
!To
lera
nces
do
not a
ffect
its
func
tion
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Food
for t
houg
ht: T
oler
ance
leve
ls in
this
mec
hani
sm?
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
e in
rela
tion
to $
$$$
�C
ost g
ener
ally
incr
ease
s w
ith s
mal
ler t
oler
ance
�Sm
all t
oler
ance
s ca
use
an e
xpon
entia
l inc
reas
e in
cos
t
�Th
eref
ore
your
dut
y as
an
engi
neer
hav
e to
con
side
r : D
o yo
u ne
ed
1.00
01in
or i
s 1.
01in
goo
d en
ough
?
�P
arts
with
sm
all t
oler
ance
s of
ten
requ
ire s
peci
al m
etho
ds o
f m
anuf
actu
ring.
�P
arts
with
sm
all t
oler
ance
s of
ten
requ
ire g
reat
er in
spec
tion
and
call
for t
he re
ject
ion
of p
arts
G
reat
er Q
ualit
y In
spec
tion
Gre
ater
cos
t.
�D
o no
t spe
cify
a s
mal
ler t
oler
ance
than
is n
eces
sary
!
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
How
are
Tol
eran
ces
Spe
cifie
d
�S
ize
�Li
mits
spe
cify
ing
the
allo
wed
var
iatio
n in
eac
h di
men
sion
(len
gth,
wid
th, h
eigh
t, di
amet
er,
etc.
) are
giv
en o
n th
e dr
awin
g�
Geo
met
ry�
Geo
met
ric T
oler
anci
ng�
Allo
ws
for s
peci
ficat
ion
of to
lera
nce
for t
he
geom
etry
of a
par
t sep
arat
e fro
m it
s si
ze�
GD
T (G
eom
etric
Dim
ensi
onin
g an
d To
lera
ncin
g)
uses
spe
cial
sym
bols
to c
ontro
l diff
eren
t geo
met
ric
feat
ures
of a
par
t
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Val
ue o
f Tol
eran
ce
�Th
e to
lera
nce
for a
sin
gle
dim
ensi
on m
ay b
e sp
ecifi
ed
with
the
dim
ensi
on a
nd th
en th
e to
lera
nce.
�Th
e to
lera
nce
is to
tal v
aria
tion
betw
een
the
uppe
r and
low
er
limits
.
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Gen
eral
Tol
eran
ces
�Th
ese
are
spec
ified
whe
n al
l dim
ensi
on in
the
draw
ings
ha
ve th
e sa
me
tole
ranc
e.�
Thes
e no
tes
are
used
to
re
duce
th
e nu
mbe
r of
di
men
sion
s re
quire
d on
a
draw
ing
and
to
prom
ote
draw
ing
clar
ity.
1 2
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
es s
peci
fied
for s
ize
�Li
mit
Tole
ranc
es �
(12.
75/1
2.25
)�
Plu
s/M
inus
Tol
eran
ces
�U
nila
tera
l Tol
eran
ces
-(12
.00
+ or
-xx
x)�
Bila
tera
l Tol
eran
ces
-(12
.00
+xxx
/-xx
x)
Thes
e to
lera
nce
valu
es in
dica
te th
e:
MM
C:M
axim
um M
ater
ial C
ondi
tion
LMC
:Lea
st M
ater
ial C
ondi
tion
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Lim
it To
lera
nces
MM
C:M
axim
um M
ater
ial C
ondi
tion
LMC
:Lea
st M
ater
ial C
ondi
tion
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Lim
it To
lera
nces
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Plu
s/M
inus
Tol
eran
ces
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Allo
wan
ce a
nd C
lear
ance
�A
LLO
WA
NC
E�
Allo
wan
ceis
def
ined
as
an in
tent
iona
l diff
eren
ce b
etw
een
the
max
imum
m
ater
ial l
imits
of m
atin
g pa
rts. A
llow
ance
is th
e m
inim
um c
lear
ance
(pos
itive
al
low
ance
), or
max
imum
inte
rfere
nce
(neg
ativ
e al
low
ance
) bet
wee
nm
atin
g pa
rts. T
he c
alcu
latio
n fo
rmul
a fo
r allo
wan
ce is
:
ALL
OW
AN
CE
= M
MC
HO
LE –
MM
C S
HA
FT
�C
LEA
RA
NC
E�
Cle
aran
ceis
def
ined
as
the
loos
est f
it or
max
imum
inte
nded
diff
eren
ce
betw
een
mat
ing
parts
.�
The
calc
ulat
ion
form
ula
for c
lear
ance
is:
CLE
AR
AN
CE
= LM
C H
OLE
–LM
C S
HA
FT
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Type
s of
Fit
�Ty
pes
of F
it�
Cle
aran
ce fi
t�
The
parts
are
tole
ranc
edsu
ch th
at th
e la
rges
t sha
ft is
sm
alle
r tha
n th
e sm
alle
st h
ole
�Th
e al
low
ance
is p
ositi
ve a
nd g
reat
er th
an z
ero
�In
terfe
renc
e fit
�Th
e m
ax. c
lear
ance
is a
lway
s ne
gativ
e�
The
parts
mus
t alw
ays
be fo
rced
toge
ther
�Tr
ansi
tion
fit�
The
parts
are
tole
ranc
edsu
ch th
at th
e al
low
ance
is
nega
tive
and
the
max
. cle
aran
ce is
pos
itive
�Th
e pa
rts m
ay b
e lo
ose
or fo
rced
toge
ther
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
BA
SIC
FIT
S O
F M
ATI
NG
PA
RTS
Stan
dard
AN
SI F
its:
Run
ning
and
Slid
ing
fits
(RC
)are
inte
nded
to p
rovi
de a
runn
ing
perfo
rman
ce w
ith s
uita
ble
lubr
icat
ion
allo
wan
ce. T
he ra
nge
is fr
om R
C1
to
RC
9.
Forc
e fit
s (F
N)o
r Shr
ink
fits
cons
titut
e a
spec
ial t
ype
of in
terfe
renc
e fit
ch
arac
teriz
ed b
y m
aint
enan
ce o
f con
stan
t pre
ssur
e. T
he ra
nge
is fr
om F
N1
to F
N5.
A fo
rce
fitis
refe
rred
to a
s in
terfe
renc
e fit
or a
shr
ink
fit. T
he s
mal
lest
am
ount
of i
nter
fere
nce
is:
MIN
INTE
RFE
REN
CE
= LM
C S
HA
FT -
LMC
HO
LETh
e gr
eate
st a
mou
nt o
f int
erfe
renc
e is
:
MA
X IN
TER
FER
ENC
E =
MM
C S
HA
FT -
MM
C H
OLE
Loca
tiona
lfits
are
inte
nded
to d
eter
min
e on
ly th
e lo
catio
n of
the
mat
ing
parts
.
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Sam
ple
Cal
cula
tion
Giv
en: D
iam
eter
of s
haft:
1.5
mm
Upp
er L
imit
Tole
ranc
e: 0
.03m
m
Low
er L
imit
Tole
ranc
e : 0
.04m
m
Giv
en: D
iam
eter
of H
ole:
1.4
8mm
Upp
er L
imit
Tole
ranc
e : 0
.03m
m
Low
er L
imit
Tole
ranc
e : 0
.05m
m
Ans
wer
Allo
wan
ce:
-0.1
mm
Cle
aran
ce: 0
.05m
m
Type
of F
it: T
rans
ition
Fit
Allo
wan
ce: M
MC
-Hol
e -
MM
C-S
haft
= 1.
43 �
1.53
= -
0.1m
m
Cle
aran
ce: L
MC
-Hol
e �
LMC
-Sha
ft
= 1.
51 �
1.46
= 0
.05m
m
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Geo
met
ric D
imen
sion
ing
& To
lera
ncin
g (G
D&
T)
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
e of
For
mSt
raig
htne
ss
Stra
ight
ness
Tol
eran
ce Z
one
Stra
ight
ness
Tol
eran
ce
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
e of
For
m
Not
e: 0
.16
< 0.
5 (s
ize
tole
ranc
e)
FLAT
NES
S
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
e of
For
m
Cir
cula
rity
Tol
eran
ce Z
one
Cir
cula
rity
Tol
eran
ce
Circ
ular
ity
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
e of
For
m
Cyl
indr
icity
Tol
eran
ce Z
one
Cyl
indr
icity
Tol
eran
ce
Cyl
indr
icity
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
e of
Orie
ntat
ion
Perp
endi
cula
rity
Perp
endi
cula
rity
Tol
eran
ce Z
one
Perp
endi
cula
rity
Tol
eran
ce
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
e of
Orie
ntat
ion
Para
llelis
mPa
ralle
lism
Tol
eran
ce Z
one
Para
llelis
m T
oler
ance
T: T
ange
nt P
lane
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
es in
Aut
oCA
D
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
es in
Aut
oCA
D
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Tole
ranc
es in
Aut
oCA
D
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
GEO
MET
RY
DIM
ESIO
NIN
G A
ND
TO
LER
AN
CE
FOR
CA
DD
/CA
MS
ome
dim
ensi
onin
g an
d to
lera
nce
guid
elin
es fo
r use
in c
onju
nctio
n w
ith C
AD
D/C
AM:
�G
eom
etry
tole
ranc
ing
is n
eces
sary
to c
ontro
l spe
cific
geo
met
ric fo
rm a
nd lo
catio
n.�
Maj
or fe
atur
es o
f the
par
t sho
uld
be u
sed
to e
stab
lish
the
basi
cco
ordi
nate
sys
tem
, but
are
not
ne
cess
ary
defin
ed a
s da
tum
.�
Subc
oord
inat
edsy
stem
s th
at a
re re
late
d to
the
maj
or c
oord
inat
es a
re u
sed
to lo
cate
and
orie
nt
feat
ures
on
a pa
rt.�
Def
ine
part
feat
ures
in re
latio
n to
thre
e m
utua
lly p
erpe
ndic
ular
refe
renc
e pl
ans,
and
alo
ng fe
atur
es
that
are
par
alle
l to
the
mot
ion
of C
AM e
quip
men
t.�
Esta
blis
h da
tum
rela
ted
to th
e fu
nctio
n of
the
part,
and
rela
te d
atum
feat
ures
in o
rder
of p
rece
denc
e as
a b
asis
for C
AM u
sage
.�
Com
plet
ely
and
accu
rate
ly d
imen
sion
geo
met
ric s
hape
s. R
egul
ar g
eom
etric
sha
pes
may
be
defin
ed
by m
athe
mat
ical
form
ulas
. A p
rofil
e fe
atur
e th
at is
def
ined
with
mat
hem
atic
al fo
rmul
as s
houl
d no
t ha
ve c
oord
inat
e di
men
sion
s un
less
requ
ired
for i
nspe
ctio
n or
refe
renc
e.�
Coo
rdin
ate
or ta
bula
r dim
ensi
ons
shou
ld b
e us
ed to
iden
tify
appr
oxim
ate
dim
ensi
ons
on a
n ar
bitra
ry
prof
ile.
�U
se th
e sa
me
type
of c
oord
inat
e di
men
sion
ing
syst
em o
n th
e en
tire
draw
ing.
�C
ontin
uity
of p
rofil
e is
nec
essa
ry fo
r CAD
D. C
lear
ly d
efin
e co
ntou
r cha
nges
at t
he c
hang
e or
poi
nt o
f ta
ngen
cy. D
efin
e at
leas
t fou
r poi
nts
alon
g an
irre
gula
r pro
file.
�C
ircul
ar h
ole
patte
rns
may
be
defin
ed w
ith p
olar
coo
rdin
ate
dim
ensi
onin
g.�
Whe
n po
ssib
le, d
imen
sion
ang
les
in d
egre
es a
nd d
ecim
al p
arts
of d
egre
es.
�Ba
se d
imen
sion
s at
the
mea
n of
a to
lera
nce
beca
use
the
com
pute
r num
eric
al c
ontro
l (C
NC
) pr
ogra
mm
er n
orm
ally
spl
its a
tole
ranc
e an
d w
orks
to th
e m
ean.
Whi
le th
is is
theo
retic
ally
des
irabl
e,
one
can
not p
redi
ct w
here
the
part
will
be m
ade.
Dim
ensi
ons
shou
ld a
lway
s be
bas
ed o
n de
sign
re
quire
men
ts. I
f it i
s kn
own
that
a p
art w
ill be
pro
duce
d al
way
sby
CN
C m
etho
ds, t
hen
esta
blis
h di
men
sion
s w
ithou
t lim
its th
at c
onfo
rm to
CN
C m
achi
ne c
apab
ilitie
s. B
ilate
ral p
rofil
e to
lera
nces
are
al
so re
com
men
ded
for t
he s
ame
reas
on.
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Furth
er R
eadi
ng�
��
Inte
rpre
tatio
n of
Geo
met
ric D
imen
sion
ing
& To
lera
ncin
g by
Dan
iel E
. P
unco
char
�G
eom
etric
Dim
ensi
onin
g an
d To
lera
ncin
g by
Ale
x K
rulik
owsk
i
�G
eo-M
etric
s III
: Th
e Ap
plic
atio
n of
Geo
met
ric D
imen
sion
ing
and
Tole
ranc
ing
Tech
niqu
es (U
sing
the
Cus
tom
ary
Inch
Sys
tem
s) b
y Lo
wel
l W. F
oste
r
�To
lera
nce
desi
gn :
a ha
ndbo
ok fo
r dev
elop
ing
optim
al s
peci
ficat
ions
by
C.M
. Cre
velin
g.
�D
imen
sion
ing
and
Tole
ranc
ing
Han
dboo
k by
Pau
l J. D
rake
�In
spec
tion
and
Gag
ing
by C
liffo
rd W
. Ken
nedy
�G
eom
etric
Dim
ensi
onin
g an
d To
lera
ncin
g by
Cec
il H
. Jen
sen
�To
lera
nce
Sta
ck-U
p An
alys
is b
y Ja
mes
D. M
eado
ws
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Hom
e W
ork
#2
1. F
ind
T H, T
s, A
llow
ance
, Cm
ax, C
min
, and
wha
t kin
d of
fit i
t is ?
Hol
e F
66 u
pper
dev
iatio
n +0
.051
, low
er d
evia
tion
0.0
Shaf
t F 6
6 up
per d
evia
tion
-0.0
24, l
ower
dev
iatio
n -0
.050
2. F
ind
T H, T
s,A
llow
ance
, Cm
ax, I
max
, and
wha
t kin
d of
fit i
t is ?
Hol
e F
32 u
pper
dev
iatio
n +0
.021
, low
er d
evia
tion
0.0
Shaf
t F 3
2 up
per d
evia
tion
+0.0
29, l
ower
dev
iatio
n +0
.016
3. If
a sh
aft i
s 10
0.05
inch
wha
t is i
ts m
axim
um a
nd le
ast m
ater
ial
cond
ition
s.4.
Ple
ase
draw
circ
ular
ity a
nd p
erpe
ndic
ular
ity sy
mbo
l blo
cks
with
geo
met
ric to
lera
nce
of 0
.005
for e
ach,
and
sket
ch th
eir
tole
ranc
e zo
nes f
or a
cyl
inde
r and
a u
psid
e do
wn
T sh
ape
bloc
k re
spec
tivel
y.
Dep
artm
ent o
f Mec
hani
cal E
ngin
eerin
g an
d M
echa
nics
Hom
e W
ork
#2 c
ontd
..
�Ref
er N
otes
and
Aut
oCA
D te
xt b
ook
for h
elp
in s
olvi
ng p
robl
ems.
�Hom
e w
orks
sho
uld
incl
ude
your
nam
es a
nd th
e se
ctio
n yo
u be
long
to.
�Will
be
due
durin
g th
e ne
xt L
ectu
re C
lass
.
T h=
tole
ranc
e of
hol
eT s
= To
lera
nce
of s
haft
Cm
ax=
Max
imum
cle
aran
ceC
min=
Min
imum
cle
aran
ceI m
ax=
Max
ium
umin
terfe
renc
e
F66
and
F32
indi
cate
s th
e no
min
al d
imen
sion
s of
the
hole
or s
haft
