12 surface texture symbols permission granted to reproduce for educational use only. explain common...

12 Surface Texture Symbols

Permission granted to reproduce for educational use only.

• Explain common terms related to surface quality and surface texture symbols.

• Identify and interpret the components of surface texture symbols.

• Identify lay symbols used in surface texture symbols.


• Describe the units used by various values within surface texture symbols.

• Explain standard practices for applying surface texture symbols on a print.

• Identify special designations related to surface quality that may appear on a print.


Surface Texture Terms

• Surface texture is the overall roughness, waviness, lay, or flaws of a surface


Surface Texture Terms

• Roughness height examples


Surface Texture Symbols

• In the past, finished surfaces were identified with finish marks, as shown here

• Surface texture symbols are now used instead


Surface Texture Symbol

• A—Basic surface texture symbol• B—Material removal is required by machining• C—Indicates a minimum amount that must be

removed• D—Material removal is prohibited• E—Horizontal bar to help locate parameters and

values


Surface Texture Values

• (a) Average roughness value (in microinches or micrometers)

• (b) Optional production method (i.e., MILL or GRIND)

• (c) Roughness cutoff or sampling length• (d) Optional lay symbol


Surface Texture Values

• (e) Minimum material removal (inches or millimeters)

• (f) Roughness parameter other than arithmetic average


Lay Symbols

• Lay symbols are not required• If used, there are seven options


Lay Symbols


Applying Surface Texture Symbols

• Surface texture symbols can be attached to:– Surface “edge views”– Extension lines– Leader line shoulders– Placed in a note


• What is the difference between surface texture and surface roughness?

Surface texture is the overall roughness, waviness, lay, or flaws of a surface, while surface roughness is the fine irregularities in the surface texture.


• Which microinch value appearing in a surface texture symbol indicates the finer finish, 8 or 1000?

8


• When the symbol appears in the surface texture symbol, what does it indicate?

It is a lay symbol that means the lay is perpendicular to the edge view line to which the texture symbol is applied.


• If the value .06 appears under the horizontal bar in a surface texture symbol, what does this mean?

It specifies a roughness cutoff, or sampling length, of .06 inches.


• List three methods that may be used to place surface texture symbols on a drawing in order to reduce clutter in a view.

Place the symbol on an extension line or leader line to the edge view of the feature or include the symbol in a note.


• What is surface mismatch?

An uneven blend on a machined surface resulting from multiple passes of a cutter.

12 surface texture symbols permission granted to reproduce for educational use only. explain common...

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