1838

cagd

M

3.23.2

(b)

6.3

1.66.3

(b)(a)

(a)

1.6

25

6.3

(c)

25

25

(b)

6.3

25

(a)

bfcV

de ge

Excerpt from JIS B 0031(1994)

Trace Left by a Cutting Instrument

Trace Left by a Cutting Instrument

Trace Left by a Cutting Instrument

The pattern left by a cutting instrument is virtually radial around the center of theplane in the drawing.

Ex. Faced Surface

The pattern left by a cutting instrument is virtually concentric around the center ofthe plane in the drawing.

Lapped Surface, SuperfinishedSurface and Surface Finishedwith a Front Mill or End Mill

Ex.

The pattern left by a cutting instrument crossesin various directions or has no grain direction.

Ex. Honed Surface

The pattern left by a cutting instrument diagonally crosses the projection plane inthe drawing.

Circular Cut, Cylindrical CutEx. Shaped Surface (Side View)

The trace left by a cutting instrument isperpendicular to the projection plane inthe drawing.

Ex. Shaped Surface

The trace left by a cutting instrumentis parallel to the projection plane in the drawing.

Machining Method

Upper and Lower Limits of Ra

Grain Direction

Upper Limit of Ra

Removal of Material is Prohibited

Removal of Material by Machining is Required

Surface Symbol

IExamplesIllustrationMeaningSymbol

A surface roughness value, cut-off value or reference length, processing method, grain direction,surface undulation, etc. are indicated around the surface symbol as shown in Fig. 1 below.

Under ISO 1302, a finish range should be indicated as e in Fig. 1.Remark:

Remark: These symbols except a and f are provided when they are needed.

g

f

d

c

cV

b

a

:Surface Undulation(according to JIS B 0610)

:Parameter other than Ra(tp:Parameter/Cut-Off Level)

:Grain Direction

:Reference Length, Evaluation Length

:Cut-off Value, Evaluation Length

:Machining Method

:Ra Value

Fig. 1. Positions of Auxiliary Symbols

1. Positions of Auxiliary Symbols for Surface Symbol

Drawing Indication of Surface Texture’Technical Data»

Milling

1837

5+Yv4

X

) d◊ x1r f(Ra=

0

r

5Yv 1+Yv +Yv2 +Yv35+3+Yp +Yp42+Yp+Yp1Yp

Rz=

m

5YpYp

4

V5Y

3YpYp

2

YV4Y V

3

YV2

1

V1Y

Yp

Rp

Ry=Rp+Rv

m

Rv

Ry

r

0

Ra

Y

r

~zz

zz100

200400

50

12.525

zz

1.63.26.3

zzz

0.050.10.20.40.8

zz

zzzs

ssss

0.80.40.20.10.05

sss

6.33.21.6

ss

ss

ss

2512.5

50

400200

100

~50 100

2512.5 ~

~3.2 6.3

1.60.4 ~

~0.012 0.2

aaaaa

0.20.10.050.0250.012

aaa

1.60.80.4

aa

6.33.2

12.5 aa25

50 aa100

RzRy

m

r(mm)0.08

0.25

2.5

-

8

0.8

-

2.5

8

0.8

0.25

0.08

Ra

r

Excerpt from JIS B 0601(1994)and JIS B 0031(1994)

Definitions and presentations of arithmetic average roughness(Ra), maximum height(Ry), 10-spot average roughness(Rz),average concave-to-convex distance(Sm), average distance between local peaks(S)and load length rate(tp)are given asparameters indicating the surface roughness of an industrial product. Surface roughness is the arithmetic average of values atrandomly extracted spots on the surface of an object.’Center-line average roughness(Ra 75)is defined in the supplements to JIS B 0031 and JIS B 0601.»

Levels of the lowest trough to the fifth highest trough in thesaid portion with the lengthr.

Levels of the highest peak to the fifth highestpeak in the said portion with the lengthr.

*Interrelations among the three varieties shown here are not precise, and are presented for convenience only.

Ten-Spot Average RoughnessMax.Height

Reference:Relation between Arithmetic Average Roughness(Ra)and Conventional Parameters

A portion stretching over a reference length in the direction in which the average line extends is cut out from the roughness curve. The averageof the levels(Yp)of the highest peak to the fifth highest peak as measuredfrom the average line and the average of the levels(Yv)of the lowesttrough to the fifth lowest trough similarly measured in the said portion are added together. Rz is this sum, in microns(Om).

Ten-Spot Average Roughness, Rz

Remark:A portion without an abnormally high peak or abnormally low trough, which may be regarded as a flaw, is cut out over the reference length.

A portion stretching over a reference length in the direction in whichthe average line extends is cut out from the roughness curve. The gapbetween the peak line and the trough line is measured in the directionin which the magnitude axis extends, in microns(Om).

Maximum Height, Ry

A portion stretching over a reference length in the direction in whichthe average line extends is cut out from the roughness curve. Thisportion is presented in a new graph with the X axis extending in thesame direction as the average line and the Y axis representing themagnitude. Ra is represented by the equation shown at right, inmicrons(Om).

Arithmetical Average Roughness, Ra

Typical Calculations of Surface Roughness

1. Varieties of Surface Roughness Indicators

*Ra:The evaluated values of Ry and Rz are the cut-off values and the reference length each multiplied by five, respectively.

Standard Series Graphical Representation of Surface Texture Standard Series

ConventionalFinish Symbol

ReferenceRy/Rz Length

Cut-Off Valuec(mm)

Arithmetic Average Roughness

Surface Roughness’Technical Data»

Yv1,Yv2,Yv3,Yv4,Yv5 :

Yp1,Yp2,Yp3,Yp4,Yp5

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