References
■ Surface Roughness ● Types and Definitions of Typical Surface Roughness Type Symbol Method of Determination
● Relationship with triangular symbol display Designated
Designated values for 10-point average roughness *2) (Rz JIS )
Descriptive Figure
Designated values for calculated average roughness (Ra)
values for maximum height *1) (Rz)
Standard reference L length value ( mm )
This value is found by extracting the reference length in the mean line direction from the surface roughness curve, measuring the intervals between the peaks and valleys in the extracted area in the longitudinal magnification direction of the surface roughness curve, and expressing this value in micrometres (μm). Remarks: When finding Rz,
* Triangular Symbols
(0.05) 0.1 0.2 0.4
(0.012) 0.025
(0.05) 0.1 0.2 0.4
m
N
*1) Rz
0.05 0.10
L
0.25
Rz=Rp+Rv
any areas deemed to be scratches are removed before extracting the reference length from an area with no high peaks or low valleys.
0.8
0.20
0.8
1.6 3.2 6.3
0.40 0.80 1.6
1.6 3.2 6.3
0.8
This value is found by extracting the reference length in the mean line direction from the roughness curve, taking the average line direction of the extracted area as the X-axis and the longitudinal magnification direction as the Y-axis and expressing the value found by the equation below in micrometres (μm) with the roughness curve expressed by y=f(x). This value is found by extracting the reference length in the mean line direction from the roughness curve, finding the sum of the mean absolute peak height taken from the five highest peaks (Yp) and the mean absolute valley height taken from the five lowest valleys (Yv) measured in the longitudinal magnification direction from the average line direction of the extracted area and expressing this value in micrometres (μm).
12.5 (18) 25 (35) 50 (70) 100 (140) 200 (280) 400 (560)
12.5 (18) 25 (35) 50 (70) 100 (140) 200 (280) 400 (560)
3.2 6.3
2.5
m
Ra
L
L
1
12.5 25
Ra=
{f(x)}dx
8
L
0
(50) (100)
— —
m
*2) Rz JIS
L
Remarks: The designated values in ( ) do not apply unless otherwise stated. * Finish symbols (triangular symbol ( ▽ ) and tilde (~)) were removed from JIS in the 1994 revision.
(Yp 1 +Yp 2 +Yp 3 +Yp 4 +Yp 5 )+(Yv 1 +Yv 2 +Yv 3 +Yv 4 +Yv 5 ) 5
Rz JIS =
Designated values for the above types of maximum height (Rz) *1) , 10-point average roughness (Rz JIS ) *2) , calculated average roughness (Ra) classifications, and reference length M are shown on the table at right with triangular symbols. *1) The maximum height symbol (Rz) is calculated according to the new JIS B 0601:2001 standard. (This value was Ry under the old standard.) *2) The 10-point average roughness (Rz JIS ) is calculated according to the new JIS B 0601:2001 standard. (This value was Rz under the old standard.)
N77
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