Tolerance PartOne Latest
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Transcript of Tolerance PartOne Latest
Tolerancing
Part 1
Interpreting, Specifying,Manufacturing & Measuring
Various Dimensional Tolerances
Specification For
Paper Sizes
Paper Sizes
Series of Sizes:
• Based on Width : Length = 1 :
•Each next smaller size has an area = Half that of previous bigger size
•Next smaller size produced by halving the longer dim(retaining the shorter dim as the new length)
Paper Sizes
A0 = 841 X 1189 = 1.0000 m2
A1 = 594 X 841 = 0.5000 m2
A2 = 420 X 594 = 0.2500 m2
A3 = 297 X 420 = 0.1250 m2
A4 = 210 X 297 = 0.0625 m2
Tolerancing
Tolerance = Permissible Variation
To be specified only when & where essential for functionality
Tolerancing
Cost of
Mfg
Tolerance
Costly Zone Optimum Zone
Tolerancing
Tolerance
Dimensional
• Dia
• Length
Tolerancing
Tolerance
Dimensional Form
• Circular
• Straightness
• Cylindricity
Variation of actual condition of form feature(Surface/line) from geometrically ideal position
Tolerancing
Tolerance
Dimensional Form Positional
B
A
Tolerancing
Tolerance
Dimensional Form Positional Surface Finish
Tolerancing
Tolerance
Dimensional Form Positional Surface Finish
Tolerance of Size automatically limits the tolerance of form & position!
The indication of tolerance of form & position does not necessarily imply the use of any particular method of mfg..
Tolerancing
Tolerance
Dimensional Form Positional Surface Finish
Waviness
Tolerancing
General Tolerances = ?
Tolerancing
General Tolerances =
Tolerances for
Linear & Angular dimensions
without individual Tolerance Indications
Ref IS 2102(Part 1) : 1993
ISO 2768-1 : 1989
Tolerance on dims. Unless otherwise specified
CategoryClass
0.5 to 3mm
3 to 6 mm 6 to 30mm30 to
120mm
Fine ?
Medium
Coarse
ExtraCoarse
Tolerancing
Tolerancing
Examples for
• Fine
• Medium
• Coarse
• Extra Coarse Components ?
Tolerancing
“One thing at a time & that too done well is the way to happiness” AKB
Tolerancing
Examples for
• Fine : Rollers for Needle bearings
• Medium :
• Coarse :
• Extra Coarse :
Tolerancing
Examples for
• Fine : Rollers for Needle bearings
• Medium : Swiss Auto -Turned Parts
• Coarse :
• Extra Coarse :
Tolerancing
Examples for
• Fine : Rollers for Needle bearings
• Medium : Swiss Auto -Turned Parts
• Coarse : Rivet
• Extra Coarse :
Tolerancing
Examples for
• Fine : Rollers for Needle bearings
• Medium : Swiss Auto -Turned Parts
• Coarse : Rivet
• Extra Coarse : Forged part
Tolerancing
Examples for
• Fine : Rollers for Needle bearings
• Medium : Swiss Auto -Turned Parts
• Coarse : Rivet
• Extra Coarse : Forged part
Note: Hybrid Tolerancing not allowed!
Tolerancing
Tolerance on dims. Unless otherwise specified
CategoryClass
0.5 to 3mm
3 to 6 mm 6 to 30mm30 to
120mm
Fine +/-0.05
Medium ?
Coarse
ExtraCoarse
Tolerancing
Tolerance on dims. Unless otherwise specified
CategoryClass
0.5 to 3mm
3 to 6 mm 6 to 30mm30 to
120mm
Fine +/-0.05
Medium +/-0.10
Coarse ?
ExtraCoarse
Tolerancing
Tolerance on dims. Unless otherwise specified
CategoryClass
0.5 to 3mm
3 to 6 mm 6 to 30mm30 to
120mm
Fine +/-0.05
Medium +/-0.10
Coarse +/-0.30
ExtraCoarse
?
Tolerancing
Tolerance on dims. Unless otherwise specified
CategoryClass
0.5 to 3mm
3 to 6 mm 6 to 30mm30 to
120mm
Fine +/-0.05
Medium +/-0.10
Coarse +/-0.30
ExtraCoarse
+/-0.50
Tolerancing
Tolerance on dims. Unless otherwise specified
CategoryClass
0.5 to 3mm
3 to 6 mm 6 to 30mm30 to
120mm
Fine +/-0.05 +/-0.05 +/-0.15 +/-0.2
Medium +/-0.10 +/-0.10 +/-0.20 +/-0.30
Coarse +/-0.20 +/-0.30 +/-0.50 +/-0.80
ExtraCoarse
NA +/-0.50 +/-1.00 +/-1.50
Tolerancing
Exclusive For Tool Drawings:
20,0 = 20+/-0.5
Tolerancing
Exclusive For Tool Drawings:
20,0 = 20+/-0.5
20,00 = 20+/-0.05
Tolerancing
Exclusive For Tool Drawings:
20,0 = 20+/-0.5
20,00 = 20+/-0.05
20,000 = 20+/-0.005
Tolerancing
Company Standards for general Tolerances
IS 2102 for ‘Rubber Parts’ Anecdote
Tolerancing
“Loose Tolerances tightly held are better than tight tolerances loosely held”
Centurion
Tolerancing
ASSEMBLY
Interchangeable Assembly
Graded Assembly
Selective Assembly
? ? ?
Tolerancing
Tolerance
Min Bore Max Bore
BORE FEATURES
Tolerancing
Tolerance
Min Bore Max Bore
BORE FEATURES
Dist. Between axes = ?
Tolerancing
Combined Representation of Bore
Min?
Max?
Tol?
Tolerancing
Tolerance
Max Shaft
Min Shaft
SHAFT FEATURES
Tolerancing
Tolerance
Max Shaft
Min Shaft
Combined
Representation
SHAFT FEATURES
Tolerancing
Basic Size of Bore
Basic Size of Shaft
Tolerancing
Line of zero deviation
Basic Size
Lower Deviation
Upper Deviation
BORE FEATURES
Tolerancing
Line of zero deviation
Lower Deviation
Upper Deviation
Basic Size
SHAFT FEATURES
Tolerancing
Line of zero deviation
Lower Deviation
Lower Deviation
Upper Deviation
BORE & SHAFT FEATURES
Upper Deviation
Basic Size
Tolerancing
Feature Deviation
Bore Shaf t
Upper Max MaxLower Min Min From Basic Size
Tolerancing
Feature Deviation
Bore Shaf t
Upper ES esLower EI ei* From Basic Size
Tolerancing
FEATUREDEVIATION *
BORE SHAFT
UPPERLOWER
* FROM BASIC SIZE
Tolerancing
Line of zero deviation
EI
ei
es
BORE & SHAFT FEATURES
ES
Basic Size
Does Tolerance have a sign?
Answer in Part 2
Tolerancing