E25 Lec 18-22 GD&T
Transcript of E25 Lec 18-22 GD&T
ENGR 25 Graphics Powerpoints: Geometric Dimensioning & Tolerancing
8/10/2020
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GD&T
Geometric Dimensioning & Tolerancing (GD&T)
Rule #1
Size limits envelope
Section10
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Rule #1:“Unless otherwise specified, the limits
of size of a feature prescribe the extent within which variations of geometric form, as well as size, are allowed.”
ASME Y14.5
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Ø11.8
(B)
(C)
Ø12.2
Ø11.8
Ø12.2
Ø11.8
Ø12.2
Ø11.8
Ø12.2
Ø11.8 for entire length Ø11.8 for entire length
External dowel plug Internal hole
(A)
at Ø12.2 MMC must be perfect form
at Ø11.8 MMC must be perfect form
Ø12.211.8
Ø12.211.8
When only size tolerance is specified,the object’s form can vary within the stated size limits.
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(A) (B) (C)
Min Min Min
Max Max Max
A cylinder can have a variety of shapes yet stay within the limits of size.
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1614
119
97
2220
7
8(A) (B)
1816
The rectangular prism can vary in shape as long as it stays inside the volume of the limits of size.
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16.015.8
Ø8.0 MMC
Ø7.8 LMC alongentire lengthof dowel
Ø6.8MMC
Ø7.0LMC
Ø7.06.8
Ø8.07.8
Ring gage
Plug gage
(A) Checking geometric form with ring gage
(B) Checking geometric form with plug gage
A ring gage and plug gage are used to check the geometric form of a pin and hole.
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Geometric Dimensioning & Tolerancing (GD&T)
Section10 Datums
Datum axis
Order of Datums
Checking compliance
Compound & coplanar datums
Chain lines & partial datum surfaces
Datum target points
Datum target line
Datum target areas
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Datumfeature
Simulateddatum(surface plate)
Measuredheight
Dial face
ProbeUp
Down
A height gage measures the height of an object from the simulated datum surface of a surface plate.
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+Y
-X+Z
-Y
+X
-Z
Degrees of freedom allow movement in two directions along each axis and rotation about each axis.
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A datum reference frame consists of three intersecting planes at 90° to each other.
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2H for single lettering4H for double lettering
A2H H
H
60°
16
G
H
E
F
Filled orunfilled
(A) H = height of lettering
(B) Applications
Varies
(A) Illustrates the method for drawing the datum symbol while (B) illustrates some applications.
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KJ
J
Ø14Ø8
Ø14
J
-or-
The datum symbol is applied to solid cylinders.
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F G HØ0.1
Ø12
N
P
RM
Ø6
Ø12
Ø6
M
The datum symbol is applied to holes.
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(A)This drawingsymbology
(B) Means this
SU
T
3 pts of contact1 pt of contact
2 pts of contact
S T UØ0.1
TS12
2X Ø6 ± 0.2
6
M
8
U
10
Primary datum S has 3 pts of contact, T 2 pts and U 1pt of contact.
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(1 pt)
(2 pts)
(3 pts)
V W XØ0.1
2X Ø6 ± 0.08M
X
W
V
(1 pt) (3pts)
(2 pts)
Trueheight
VX
W
Correct inspection procedure
True width(1 pt)
(3 pts)(2pts)
VX
W
Falseheight
Incorrect inspection procedure
Falsewidth
The order of the datums is critical!
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GH
(A) This drawing
8
8
8 8
Ø24
0.5 G H4X Ø4±0.5 Intersecting planes
perpendicular to G
Primarydatum G
Datum axis
(B) Means this
The datum axis is formed by two intersecting planes.
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(A) This drawing
(B) Means this
C
Ø10.8±0.1
Simulated datumcylinder C - largest Ø that fits into hole
Datum axis
Datum feature C
Plug gage
The plug gage establishes the datum axis.
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(A) This drawing
(B) Means this
D
Datum feature DSimulated datum D
Datum axis
19±0.5
The smallest circumscribed cylinder establishes the simulated datum and the datum axis.
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B) Means this
A) This drawing 24.223.8
12.211.8
0.4 Y Z
Z
Y
Central datum plane
Simulateddatums atmaximumseparation
Datum features
The simulated central datum plane is established by the center plane of the largest block that fits into the groove.
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B) Means this
A) This drawing
18.2
Simulated datumplanes at minimumseparation
Central datum plane
0.6 A B
B
A
17.8
The simulated central datum plane is established by the center plane located by the two blocks at minimum separation.
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(A) This drawing
(B) Means this
E F
Ø8±0.2 Ø9±0.2
0.5 E-F
Three jawed coaxial chucks
Datum axis E-F
Datum feature ESimulated datum E
Datum feature FSimulated datum F
This compound datum holds the object at both its ends in order to check runout.
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X Y
Simulatedcoplanardatum X-Y
Datum feature X
Datumfeature Y
A) This drawing
B) Means this
.08 X-Y
Datum features X and Y establish a coplanar datum.
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(A) This drawing
(B) Means this
G
9
9
22Chain line
Simulateddatum
Datum feature
The 22 chain line determines the area of the datum feature.
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A1
B1 C1Ø8
Ø.750
Datum point orLine ID letter
Datum point or line number
(A) Datum point or point view of line symbol
Ø of targetarea
(C) Datum target area callout
2H
90°
(B) Datum point orline callout
Ø3.5H
Thick lines
Symbology used for the datum target point and datum target line.
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K8
28
18
12
6
K1 K2 K3
This drawing establishes datum plane K using three datum points.
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Dowel pins with
spherical radial tops
Inspection
fixture
Part
This inspection fixture uses three dowels with SR tops to establish three datum points.
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S
S1
2012
S1
When a datum point does not show in an elevation view, two adjacent dimensions locate it.
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Datum line
L
N1
148
24
M
N
M2
M1
M2
M1
Point view ofdatum line (phantom line)
N
Datum lines M1 & M2 establish the secondary datum and N1 the tertiary datum.
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3 locatordowel pinsPart
Inspectionfixture
Dowel pins establish datum lines M1 & M2 and datum line N1.
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B1 C1Ø8
Ø.750
Ø of targetarea
A datum target area callout has the area’s diameter on top and the area’s unique number on the bottom.
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20
12
T
T3
T2
T1Ø6
Ø6
Ø6
A) This drawing B) Means this
3 X Ø6 dowel pins
Inspectionfixture
Part
Three datum target areas are used to check the part’s conformance.
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(A) This drawing showing target areas
U
U3 10
U1 U218
6
12
8
22
Ø4
Ø4 Ø4
Part
Inspectionfixture
2 short dowel pins
1 longerdowel pin
(B) Means this
The three datum targets U1, U2, & U3 (which is at a different elevation) establish datum U.
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P1
10
R1P
R12
22
(Near side)(Far side)Ø6 Ø6
Datum target area P1 is located on the near side while target area R1 is on the far side of the object.
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The top half of the datum target callout is left blank since there is no circular target area.
8
12
V
6
Y1R16R8
V1
W
W1
X1
12
8
12
(A) (B)
(C) (D)
6
12
16X
16
A datum target can take on any shape.
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Geometric Dimensioning & Tolerancing (GD&T)
Section10
Dimensioning symbology
Feature control frame
Geometric characteristic symbols
Modifiers in a feature control frame
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1.5h
12Varies
Basic Dimension
ØDiameter
1.5h
.3h
1.6
2h
( )(
ST
R SR SØ CR
X
2h
h h
90°h
h
0.6h60°
h 2h
0.5h0.5h
30°
hh
h15°
2.5h
1.5h0.8h
60°
Counterbore Countersink Depth (or deep)
Dimension Origin Conical Taper Square
Arc Length Reference Slope
Radius
Places or By
Statistical Tolerance(dimensional)
SphericalRadius
SphericalDiameter
ControlledRadius
These symbols are used when dimensioning.
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2h
h h
90°
h
h
0.6h 60°
h 2h
0.5h0.5h
30°
h
h
Counterbore Countersink Depth (or deep)
Dimension Origin Conical Taper Square
h = height of lettering
These symbols are used when dimensioning.
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1.5h
12
Varies
Basic Dimension
ØDiameter
1.5h
.3h
1.6
2h
( )(
ST
R SR SØ CR
X
h15°
2.5h
1.5h0.8h
60°
Arc Length Reference Slope
Radius
Places or By
Statistical Tolerance(dimensional)
SphericalRadius
SphericalDiameter
ControlledRadius
These symbols are used when dimensioning
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0.2 A B C
Modifier
Numeric tolerance(feature tolerance)
Geometric tolerancesymbol (position)
Tertiary datumSecondary datum with modifier
Primary datum
2h
Diameter symbol
A feature control frame modifies a part’s geometry.
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0.08 0.05 A
Geometric tolerance(flatness)
Numeric tolerance
Geometric tolerance(perpendicularity)
Diameter symbolNumeric tolerance
ModifierDatum
(A) (B)
Two additional examples of feature control frames modifying a part’s geometry.
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**
Perpendicularity
Angularity
Runout Circular
Runout Total
Profile surface
Profile line
Symmetry
Cylindricity
Position
Concentricity
Circularity
Straightness
Parallelism
Flatness
Either filled or unfilled
Symbol Description
Fo
rmP
rofi
leO
rien
tati
on
Lo
cati
on
Ru
no
ut
Type oftolerance
Individualfeatures
Individual orrelated features
Relatedfeatures
Geometric Characteristic Symbols
*
Geometric characteristic symbols are categorized in two ways.
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1.5h M1.5h h 0.8h
2h1.5h
0.6h
h
1.5h
Concentricity Circularity Modifier
Straightness Parallelism Flatness
1.5h
GD&T geometric characteristic symbols illustrated.
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1.5hh
2h
h h
60°
1.5h
h
h2h
2h1.2h
0.5hCylindricity Position
All round Profilesurface
Profileline
Symmetry
GD&T geometric characteristic symbols illustrated.
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h0.8h
0.8h3h
0.6h
1.5h
2h 1.5h
30°
45°
0.6h
1.5h
1.1h
**
Perpendicularity Angularity
Runout Circular Runout Total
Between
*
Filled or unfilled*
GD&T geometric characteristic symbols illustrated.
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M
L
P
F
T
Maximum Material Condition
Least Material Condition
Projected Tolerance Zone
Free State Variation
Tangent Plane
Modifiers
ST Statistical Tolerance (geometric)
Between
Maximum Material Condition
Least Material Condition
Projected Tolerance Zone
Free State Variation
Tangent Plane
Modifiers
Between
Maximum Material Condition
Least Material Condition
Projected Tolerance Zone
Free State Variation
Tangent Plane
Modifiers
* Between
*Filled or unfilled
Table lists GD&T geometric characteristic symbol modifiers.
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Geometric Dimensioning & Tolerancing (GD&T)
Section10
Straightness
Flatness
Circularity
Cylindricity
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Ø12.412.00.03
0.03 tolzone
Ø12.4MMC
0.03 longitudinal tol zones
(A) This drawing
(B) Means this
0.03
-or-
Straightness is checked using sufficient individual line element checks to ensure its proper function.
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Adjustable jacks
LevelbarV-block
Cylindricalpart
Part
End view of V-block
Straightness can be checked using adjustable jacks and a V block.
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0.04
0.04- or -
Each line element has a 0.04 tol zonechecked with adial indicator
(B) Means this
(A) This drawing
Straightness checks individual line elements of the “treasure” chest top.
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Ø12.412.0
0.05
Ø12.4 to 12.0over entire length
Ø 0.05cylindrical
tol zone
(A) This drawing
(B) Means this
24.0
Ø12.45
Virtualcondition
Straightness applied to the diameter of the cylinder has a cylindrical tolerance zone the length of the part.
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Straightness of a central axis can be checked by taking surface error readings using opposing dial indicators.
Chuckjaws orcollet
Part
Opposingdial indicator
Straightness axial error is checked with a functional gauge whose length is equal to the pin’s length and the diameter is equal to the hole’s VC.
Ø6.05.6
0.4
PinØ
6.05.95.85.75.6
BonusTol
None0.10.20.30.4
GeomTol
0.40.50.60.70.8
Part
Ø6.4 VC
Length ofpart
VC = Virtual Condition (VC) VC = Part's MMC + Geom TolVC = Ø6.0 + Ø0.4 = Ø6.4
Straightness of a central axis is modified by either a M or L modifier.
Cylindrical tol zone Ø12.4
12.0
0.5 Ø tol zonevaries
0.05Feature
Ø
12.4 MMC12.312.212.112.0 LMC
Ø cyltol zone
0.50.60.70.80.9
0.05Feature
Ø
12.4 MMC12.312.212.112.0 LMC
Ø cyltol zone
0.50.60.70.80.9
(B) (C)
0.5-or-
(A)
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Parallel planes 0.3 apart
14.614.0
0.3
(A) This drawing
(B) Means this
14.614.0
Flatness of a surface has a tolerance zone formed by two parallel planes separated by the tolerance value.
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Part being inspectedslides on table
Dial indicatorInspection
table insection
The entire area of the part slides over the dial indicator which is poking through the inspection table.
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0.2
(A) flatness callout
A surface is called out to be flat within 0.2.
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Adjustablejacks
Dial indicator
Inspected surface
Flatness is checked by leveling the surface with adjustable jacks and inspecting with a dial indicator.
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820
1218
0.08
A specific area is checked for flatness using basic dimensions, callout, and phantom lined hatched area.
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Ø11.010.6
0.02
A
A
(A) This Drawing
Ø11.0 (Largest diameter atSection A-A)
Ø10.96(Ø11.0 - 0.04)
Ø0.02Circular
Tolerance Section A-A(B) Checked at any given cross section
-or-
Circularity requires the surface of any cross section to meet size requirements and also be within the circularity tolerance zone.
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(A) Between centers
(B) In chuck or collet
Rotate
Independentmeasurements
Rotate
Independentmeasurements
Circularity can be checked by taking independent measurements while between centers or using a chuck.
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Circularity error
Inscribedcircle
Polar graphpaper
Circularprofile
Circumscribedcircle
Circularity can be checked by plotting a circular profile on polar graph paper.
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0.4
(A) circularity callout on the cone of a nail set
(B) circularity callout on the curves of a garden tool handle
0.6
Circularity can control shapes other than cylinders.
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(A) This drawing Ø18.217.8
0.06
(B) Means this
0.06 tolerance zone
zone
2 concentric cylinders
Cylindricity requires that the entire face of the cylinder be contained between two concentric cylinders.
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Part
Dial indicator
Front Right
Ro
tate
Check cylindricity by rotating the cylinder between centers while transversing a dial indicator along top dead center.
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Rotate
Part
Spindle
Probe
Check cylindricity by rotating the cylinder in a chuck while transversing a dial indicator vertically along top dead center.
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Geometric Dimensioning & Tolerancing (GD&T)
Section10
Profile of a line
Profile of a surface
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without a datum only form is controlled
with datums, form and orientation are controlled
with datums and a basic dimension, form, orientation and location are controlled
15
B
A
0.2 A B
(C) Form, orientation, & set location of tol zone
B
A
0.2 A B
(B) Form & orientation only & floating tol zone
(A) Form only
0.2
15.114.9
Profile of a Line controls form, orientation, and location.
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(A) Simple callout (B) Tol zone 0.1 each side of perfect form
0.2
0.2
2R10
6
17
15
R9 Perfectform
The profile of a line tolerance zone is two parallel lines 0.2 apart following perfect form.
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Each line element checked separately
1
2
3
23
1
Each profile is checked separately.
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Ø3.02.8
C0.16 A B C A
B
The guitar bridge and string template’s top curve is called out with a profile of a line control.
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Hold down knob
Followertemplate
Followertip
A
B
C
Path of dial indicator
Profile of a line is checked using a follower template machined to follow perfect form.
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0.2
(A) Bilateral tolerance
(B) Unilateral tolerance out
(C) Unilateral tolerance in
0.2
0.2
0.2
0.2
0.2
Profile of a line and surface can have one of three profile zones: bilateral, unilateral in, and unilateral out.
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20 18
2 size tolerance
1.0 floatinggeometrictolerance zone
2018
2X R11
1.0
(A) This drawing
(B) Creates a floating tolerance zone with in the size tolerance
The 1.0 profile of a line tolerance zone floats within the 2 size tolerance zone.
GD&T
R10 6
17
15
R9
(A) This callout
0.4
Tol zone is twoparallel planes0.2 each side ofperfect surface
(B) Has this tolerance zone
2
Profile of a line is checked using a follower template machined to perfect form.
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7 13
R13
Ø1211
60°
A
B
0.1 A B
0.2 A B
3
Profile of a surface can be used to control spherical radius surfaces and planar surfaces.
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0.1 tol zone
0.2 tolzone
Path followingfixture template
Dial indicators follow the path of perfect form to perform inspection.
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(A) This drawing
(B) Means this Two concentric cones 0.08 apart
30°
4
26.025.8
0.08
Profile of a surface on a conical shaped router bit collet has a tolerance zone of two concentric cones.
GD&T
A
B
C
Ø3
20
6
2X R20.5 A B C
3°
Adding a circle to the elbow of the profile of a line leader means the entire surface of the slot must be checked. X
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X0.1
X Y
Y
The between symbol and labeled points designate the exact limits of the profile of a line tolerance.
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Geometric Dimensioning & Tolerancing (GD&T)
Section10
Angularity
Parallelism
Perpendicularity
GD&T
45°
0.2 A
A
(A) This drawing
0.2 widetolerancezone
(B) Means this
45°
The tolerance zone is two parallel planes 0.2 apart and on a basic 45° angle.
GD&T
Part beinginspected
Dial indicator
Gageblocks Surface
plate
Sinebar
Angularity can be checked using sine bars and gage blocks.
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(A) This drawing
60°
0.2 C D
Ø8.28.0
C
D
(B) Means this
Ø0.2 cyltol zone
Possibleorientation
The tolerance zone is a cylinder with a Ø0.2 diameter.
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Parallel surface
X0.4 X
2 planes parallel to datum X 0.4 apart
(A) Parallelism called out on a drawing
(B) Means this
(C) Checking parallelism with a dial indicator while on a surface plate
Dial indicatorSurface plate
The parallelism tolerance zone is two parallel planes 0.4 apart and parallel to the surface plate (datum X).
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7±0.1
0.4 T
T
Ø6±0.1
Ø0.4 cylindrical tolerance zone parallel to datum T
Ø12±0.1
Possible orientation
(B) Means this
(A) This drawing
7±0.1
The tolerance zone is a cylinder with a Ø0.4 diameter parallel to cylindrical datum T.
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G
Ø5.05.3
0.2 G
The hole is to be parallel to simulated datum G.
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Zero dial indicator
Check FIM
2 parallel planes 0.2 apart
Simulated datum G surface plate
12
A dial indicator checks to insure the center line is between the two parallel plates 0.2 apart.
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0.4 H
H
(A) This drawing (B) Means this
0.4 tol zone 2 parallel planes
The tolerance zone is two parallel planes 0.4 apart and perpendicular to datum H.
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Angleblock
Simulateddatum H
Datum Hfeature
Dialindicator
0.4 tol zone 2 parallel planes perpendicular to simulated datum H
Spacerblock
Perpendicularity is being checked with the aid of an angle block and dial indicator.
GD&T
0.2 G
Ø10.09.8 2 parallel planes
0.2 apart
(A) Perpendicular callout (B) Tolerance zone
This perpendicular tolerance zone is two parallel planes 0.2 part and perpendicular to datum G.X
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Geometric Dimensioning & Tolerancing (GD&T)
Section10
Virtual condition
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30.027.7J
0.3 J
Pin Ø18 MMC17.917.817.7 LMC
Geom ØTol Zone
Ø0.3Ø0.4Ø0.5Ø0.6
18.017.7Ø
(A) (B)
At MMC (Ø18mm) the tolerance is Ø0.3mm while at LMC (Ø17.7mm) the tolerance is Ø0.6mm.
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VC = 18(MMC) + 0.3(geom tol) = Ø18.3
(B) (C)
Ø18.3VCØ18MMC
Ø18MMC
Ø0.3 Cyltol zone
Ø17.7LMC
Ø0.6 Cyltol zone
Ø18 MMCperfectform
Ø18 MMCØ0.3 tolzone
Ø17.7 LMCØ0.6 tolzone
(A)
Pin is shown in three conditions: perfect, MMC, and LMC.This four part assembly has a shaft with a MMC of Ø8, a perpendicular tolerance of Ø0.4 at MMC, and a VC of Ø8.4.
VC = Virtual conditionVC = MMC of 1 Base & Shaft + geometric tolVC = Ø8.0 + Ø0.4VC = Ø8.4 Minimum hole size for 2 Bevel Gear
X
0.4 X
Ø8.07.6
4 Snap Ring
2 Bevel Gear
3 Washer
1 Base & Stud
(A) Bevel gear assembly
(B) 1 Base & Stud (C) 2 Bevel Gear
8.68.4Ø
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Geometric Dimensioning & Tolerancing (GD&T)
Section10
Positional tolerance
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16
12
10
RS
0.2 P R S 0.2 tol zone at true position of hole
P
The true position of the hole is given by basic dimensions and a Ø0.2 positional tolerance.
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8.38.0
11
11
0.4 V W
4X Ø6.05.7
W
Ø
7 7 V
11
11
0.4 V W
4X Ø6.05.7
W
Ø
7 7 V
Positional tolerance is applied to a group of holes located with basic dimensions.
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4X Ø 0.4 tol zones at true position
An array of four tolerance zones is the result of the positional callout.
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The central axes of the holes are: at true position, at extreme position, and at extreme attitude.
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U
Ø8.38.0
0.4 U V W
WV
Hole Ø Pos Tol
7.6 MMC 0.47.7 0.57.8 0.67.9 0.78.0 LMC 0.8
16
10
The table shows the positional tolerance increasing as the hole moves away from MMC.
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.04 A B C0.2 A
Pattern location tolerance
Feature relating tolerance
A composite positional tolerance is used when the location of a pattern of features is less restrictive than the hole-to-hole requirements.
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`
20
10
10
24
C
B
0.4 A B C0.2 A
4X Ø14.314.0
Pattern locating tolFeature relating tol
20
24
The red dots show the feature relating and the yellow the pattern location tolerance.
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GD&T
Position # 1 Alternate position # 2
The center axes of the holes must meet the pattern locating and feature relating tolerances simultaneously.
GD&T
Feature relating boundary – axis on edge of pattern locating boundary
Hole
Pattern location boundary at true position
A portion of the feature relating tolerance zone can spill over beyond the pattern location tolerance zone.
GD&T
0.4 A B C0.2
Pattern of holesPattern tolerance in true position
Feature tolerance
Datum CDatum B
Datum A
If no datum is specified in the second row, the central axes of the hole pattern has no orientation requirements.
A primary datum in the second row, requires the central axes to be perpendicular to the specified primary datum.
Datum CDatum B
Datum A
0.4 A B C
0.2 A
With two datums specified in the second row, the central axis of the hole pattern must be perpendicular to the primary datum and parallel to the secondary datum.
0.4 A B C
0.2 A B
Datum B
GD&T
Geometric Dimensioning & Tolerancing (GD&T)
Section10
Concentricity
Symmetry
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GD&T
(A) As drawn
(B) Axis has attitudeyet is still within Ø0.4 tol zone
(C) Axis is not concentric yet still within Ø0.4 tol zone
Ø Ø
A 0.4 A
Ø0.4 tol zone
Ø18.017.8 Ø
10.09.8
A 0.4 A
Ø0.4 tol zone
The central axis of the smaller shaft must stay within the cylindrical concentric tolerance zone of Ø0.4
GD&T
Ø18.017.8
A(A) As drawn
Ø0.4 cylindrical tol zone
Ø10.09.8
0.4 A
Ø18.0
Ø10.4
VC =Ø10.0 + 0.4
(B) Functional gage simulates mating part
A coaxial feature can be checked with a positional tol and a functional gage which simulates the mating part.
GD&T
16
24
(A) (B)
0.2 D
D
Central plane of control feature
0.2 tol zone
Central planeof feature
The central plane of the two rails are to be symmetric about a continuous 0.2 wide tolerance zone.
GD&T
Geometric Dimensioning & Tolerancing (GD&T)
Section10
Runout
Total runout
GD&T
(A) This drawing
(B) Means this
0.6 A
Ø12.011.0
0.6 A
0.6 A
-or-
-or-
A
Chuck jaws
0.6 Max FIM each measurement taken separately as part is rotated
Rotation
There are three ways to callout runout which is checked by taking individual FIM readings.
GD&T
0.4 B
0.2 B (Curve)
(Sphere)0.6 B
(Cone)
B
(A) This drawing
(B) Means thisRotate
Chuck jaws
Runout can check a variety of shapes while the dial indicator stays perpendicular to the surface.
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GD&T
0.2 JJ
0.2 Max FIM measured separately at each circular reading
Ø12.011.8
(A) This drawing
(B) Means this Rotate
On a flat surface perpendicular to the datum axis several individual circular readings must be taken.
GD&T
90°90°
YX
10 0.4 X-Y
The chain line (phantom line) and dimension designates the limit of the circular runout control.
GD&T
(B) Means this
(A) This drawing 90°90°
0.01 X-Y0.04 X-Y
0.01 X-Y0.02 X-Y
X Y
Four separate total runout readings are required on this part.
GD&T
0.02 G H
H
Ø16.215.8
Ø32.632.4
0.04 G H
Ø 8.17.7
G
(A) This drawing
Datum feature H
3 jawed chuck pressed against datum feature H
(B) Means this
Rotation
A chuck squeezes datum feature G and flat surface datum feature H is pressed tight to the chuck jaw ends.
GD&T
Geometric Dimensioning & Tolerancing (GD&T)
Section10
Projected tolerance zone
GD&T
T12 P 9 T
12 P T
(A)
(B)
M16 X 2
M16 X 2
T
9
There are two methods for specifying a projected tolerance zone.
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GD&T
Ø0.08 projected tolerance zone 12 above datum T at true position
12Part with threads
Part with clearance holeCenter line of bolt
T
The center line of the bolt must stay within the cylindrical projected tolerance zone.