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Surface Roughness

Surface Roughness

Type	Code	Determination	Determination Example (Figure)
	Ra	Ra means the value obtained by the following formula and expressed in micrometer (µm) When sampling only the reference length from the roughness curve in the direction of mean line, taking X-axis in the direction of longitudinal magnification of this sampled part and the roughness curve is expressed by y=f(x):
	Rz	Ry shall be that only the reference length is sampled from the roughness curve in the direction of mean line,the distance between the top profile peak line and the bottom profile valley line on this sampled portion is measured in the longitudinal magnification direction of roughness curve and the obtained value is expressed in micrometer (µm) Rz=Rp+Rv
	RzJIS	Rz shall be that only the reference length is sampled from the roughness curve in the direction of its mean line the sum of the average value of absolute values of the heights of five highest profile peaks (Yp) and the depth of five deepest profile valleys (Yv) measured in the vertical magnification direction from the mean line of this sampled portion and this sum is expressed in micrometer (µm)	Yp1,Yp2,Yp3,Yp4,Yp5: altitudes of the five highest profile peaks of the sampled portion corresponding to the reference length l. Yv1,Yv2,Yv3,Yv4,Yv5: altitudes of the five highest profile valleys of the sampled portion corresponding to the reference length l.