02. Surface characteristics

1.  PART AND ASSEMBLY DRAWINGS

2.  SURFACE CHARACTERISTICS

3.  DIMENSIONAL TOLERANCES

4.  FITS

5.  GEOMETRIC TOLERANCES

6.  DIMENSIONING

7.  THREADED FASTENING

8.  SHAFT AND PIPE JOINERS

9.  BEARINGS

10. GEARS 1: DEFINITION

11. GEARS 2: HELICAL

12. GEARS 3: BEVEL

13. BELTS AND CHAINS

14. WELDED JOINTS AND RIVETS

2. SURFACE CHARACTERISTICS

SURFACE CHARACTERISTICS INTRODUCTION | SYMBOLS | DRAWINGS

Industrial Drawing 2015 Ramón Rubio

It is quite convenient to check the ISO 1302:2002 standard to understand completely this lesson



We know all materials have some roughness and waviness



Waviness and roughness are not the same thing

Waviness Roughness

Waviness Roughness

Waviness Roughness

Waviness Roughness



Roughness height is one of major parameters for quantification of surface roughness. There exist different patterns for defining roughness height.



Ra: Average roughness index or height (more common). It is the height obtained dividing the area between the

roughness profile and the mean line by the evaluation length.



Rz: Mean peak-to-valley index. The distance of highest peak to deepest valley of a sample length is termed as peak-to-valley distance. Measure this peak-to valley

for five successive equal sample length to obtain Rz



Different manufacturing processes yields different amount of roughness on the surface



Basically the finer the finish and the tigher the tolerance the greater the cost. Ideally from a cost impact point of view ir is best for the designer to accept the finish and tolerance capability of the primary process.



Basic graphical symbol No specification

Name: APA (any process allowed)



Basic graphical symbol for surfaces that require

machining Name: MRR (material

removal required)

Basic graphical symbol Removal of material prohibited from the

surface Name: NMR (no material

removal)





Profile parameters

16%-rule Max rule



Surface lay orientation



ü  Process shall remove material

Examples…



ü  Process shall remove material ü  Unilateral upper specification limit

Examples…



ü  Process shall remove material ü  Unilateral upper specification limit ü  Machining process: turning

Examples…



ü  Process shall remove material ü  Unilateral upper specification limit ü  Machining process: turning ü  Roughness mean peak-to-valley: 3,2 µ

Examples…



ü  Process shall remove material ü  Unilateral upper specification limit ü  Machining process: turning ü  Roughness mean peak-to-valley: 3,2 µ ü  16%-rule (default)

Examples…



ü  Process shall remove material ü  Unilateral upper specification limit ü  Machining process: turning ü  Roughness mean peak-to-valley: 3,2 µ ü  16%-rule (default) ü  Default filter window

Examples…



ü  Process shall remove material ü  Unilateral upper specification limit ü  Machining process: turning ü  Roughness mean peak-to-valley: 3,2 µ ü  16%-rule (default) ü  Default filter window ü  Parallel orientation

Examples…



ü  Process shall remove material ü  Unilateral upper specification limit ü  Machining process: turning ü  Roughness mean peak-to-valley: 3,2 µ ü  16%-rule (default) ü  Default filter window ü  Parallel orientation ü  Evaluation length of 5 sampling length (default)

Examples…



ü  Process shall remove material ü  Unilateral upper specification limit ü  Filter window: 0,008-0,8 mm ü  Roughness: Rz=3,2 µ ü  16%-rule (default) ü  Evaluation length of 5 sampling length

(default)

ü  Process shall remove material ü  Double-sided upper and lower

specification limits ü  Machining process: turning ü  Upper limit: Roughness: Ra=0,8 µ (16%-

rule) ü  Lower limit: Roughness: Ra=0,2 µ (16%-

rule) ü  Default filter window ü  Evaluation length of 5 sampling length

(default)

Examples…



You can find different symbols that have changed throughout time



Same surface texture on any surface of the part



Same surface texture on any surface of the part (different indication)



Same surface texture …except in two faces



Alternative use of leader lines



The general rule is that the graphical symbol together with the complementary information shall be oriented so that they can be read from the bottom or right-hand side of the drawing, in conformity with ISO 129



Autodesk Inventor allows you to include the symbol in your drawings (Annotate tab)



http://www.ted.com/talks/katherine_kuchenbecker_the_technology_of_touch

Time to watch a TED talk related to the technology of touch

1.  PART AND ASSEMBLY DRAWINGS

2.  SURFACE CHARACTERISTICS

3.  DIMENSIONAL TOLERANCES

4.  FITS

5.  GEOMETRIC TOLERANCES

6.  DIMENSIONING

7.  THREADED FASTENING

8.  SHAFT AND PIPE JOINERS

9.  BEARINGS

10. GEARS 1: DEFINITION

11. GEARS 2: HELICAL

12. GEARS 3: BEVEL

13. BELTS AND CHAINS

14. WELDED JOINTS AND RIVETS

2. SURFACE CHARACTERISTICS

Design

02. Surface characteristics