1. ME 251 Anupam Saxena Professor Mechanical Engineering
Compliant and Robotic Systems Lab
Indian Institute of Technology Kanpur

2. PART AND ASSEMBLY DRAWINGS: EXAMPLE II
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II

3. PART AND ASSEMBLY DRAWINGS: EXAMPLE II
NON-RETURN VALVE 20
φ190
φ140
φ200
140
φ200
140
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II
Prepared by Anupam Saxena, Vitthal Khatik and Ishu Agrawal

4. PART AND ASSEMBLY DRAWINGS: EXAMPLE II
NON-RETURN VALVE
φ25 25
45֯ 12 48
φ90
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II
Prepared by Anupam Saxena, Vitthal Khatik and Ishu Agrawal

5. PART AND ASSEMBLY DRAWINGS: EXAMPLE II
NON-RETURN VALVE 6
φ112 45
φ90
φ100
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II
Prepared by Anupam Saxena, Vitthal Khatik and Ishu Agrawal

6. PART AND ASSEMBLY DRAWINGS: EXAMPLE II
φ190
NON-RETURN VALVE
φ120
6 HOLES,DIA 18
PCD 150
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II

7. THREADED FASTENERS Bolts and nuts- size and proportions
Representation types:
Detailed
B. Schematic
C. Simplified D 2D
30o
0.75 D
R=1.5D L 2D D D
Ref:

8. THREADED FASTENERS Bolts and nuts- size and proportions
Representation types:
Detailed
B. Schematic
C. Simplified D 2D
30o
0.75 D
R=1.5D L 2D
A bit more work but
‘realistic feeling’ D D
Ref:

9. THREADED FASTENERS Bolts and nuts- size and proportions
Representation types:
Detailed
B. Schematic
C. Simplified D 2D
30o
0.75 D
R=1.5D L 2D
A LOT more work
‘TRUE LOOK’ D D
Ref:

10. PART AND ASSEMBLY DRAWINGS: EXAMPLE II
NON-RETURN VALVE 28
M10
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II
Prepared by Anupam Saxena, Vitthal Khatik and Ishu Agrawal

11. PART AND ASSEMBLY DRAWINGS: EXAMPLE II
NON-RETURN VALVE 60 20
M16
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II
Prepared by Anupam Saxena, Vitthal Khatik and Ishu Agrawal

12. NON-RETURN VALVE: ASSEMBLY PART AND ASSEMBLY DRAWINGS: EXAMPLE II
COMMON MISTAKES
Direction of hatch lines … ?
Careful of EXTRA lines when
ASSEMBLING
The top right corner…
Make sure to number parts
and prepare the BILL of material
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II
Prepared by Anupam Saxena, Vitthal Khatik and Ishu Agrawal

13. Revisiting Tolerances
Terminology
Actual Size – Actual measured dimension of the part.
Basic Size – The size with reference to which the limits of size are fixed.
Zero Line – It is the straight line corresponding to basic size. Deviations are measured from this line.
Tolerance
Zero line
Basic size
Min. Diameter
Max. Diameter

14. Tolerances
Limit of Size – The two extreme permissible sizes of a part between which the actual size should lie.
Maximum Limit of Size – The greater of the two limits of size.
Minimum Limit of Size – The smaller of the two limits of size.
Tolerance zone – Difference between the minimum and maximum limit size.
Upper Deviation – It is the algebraic difference between the maximum size and the basic size.
Lower Deviation - It is the algebraic difference between the minimum size and the basic size.
Lower deviation
Upper deviation
Tolerance
Upper deviation
Lower deviation
Tolerance
Zero line
Max. Diameter
Min. Diameter
Basic size

15. Tolerances Specification of Tolerances Dimensional Geometric
Dimensional Tolerance – Amount by which a specified dimension is allowed to vary.
Geometric Tolerance – These are applied to features.

16. Tolerances Specification of Dimensional Tolerances
Unilateral Tolerance
Bilateral Tolerance
Unilateral Tolerance
Dimension of part is permitted to vary only on one side of the basic size: 20
0.4
Bilateral Tolerance
Dimension of part is permitted to vary both sides of the basic size: 20
-0.3
0.4

17. Tolerances Designation of Tolerance 25 H 7 f 6
IT Tolerance grade of hole
25 H 7 f 6
IT Tolerance grade of shaft
Basic size of hole and shaft
Fundamental deviation of hole
Fundamental deviation of shaft
Details to follow later …

18. PART AND ASSEMBLY DRAWINGS: EXAMPLE II
Think where you would want
to provide tolerances ?
Guesstimate on what kind?
ANUPAM SAXENA
ME 251 LECTURE III
PART AND ASSEMBLY DRAWINGS: EXAMPLE II