TECHNICAL DATA TECHNICAL DATA SURFACE …

1 PD-4 1st TECHNICAL data TECHNICAL data . SURFACE ROUGHNESS Excerpt from JIS B 0601(1994)and JIS B 0031(1994) TECHNICAL DRAWINGS METHOD OF INDICATING SURFACE . TEXTURE ON DRAWINGS. Excerpt from JIS Z B 0031(1994). Categories of SURFACE roughness Positions of respective indicating symbols relative to indicating symbol of SURFACE Definitions and indications for SURFACE roughness parameters(for industrial products)are specified. They are arithmetical mean roughness(Ra), Each grain SURFACE position is indicated as shown in Fig. includes SURFACE roughness, maximum height(Ry), ten-point mean roughness(Rz), mean spacing of profile irregularities(Sm), mean spacing of local peaks of the profile(S) cut-off value or reference length, processing method, symbol of direction of lay, SURFACE waviness, etc. and profile bearing length ratio(tp). SURFACE roughness is given as the arithmetical mean value for a randomly sampled area.

2 [Mean center line Fig. 1 Legend roughness(Ra 75)is defined in the annexes of JIS B 0031 and JIS B 0061]. a :Value of Ra b :Processing method Typical ways for obtaining SURFACE roughness b f c :Cutoff value. Evaluation length 1 r a c Arithmetical mean roughness(Ra) Ra= r f( x ) d x c c :Reference length. Evaluation length Y 0 e d g e d g m d :Symbol of direction of lay A section of standard length is sampled from the mean line on the roughness chart. The mean line is laid on a Cartesian coordinate f :Parameter other than Ra(With tp, parameter/cutoff level). system wherein the mean line runs in the direction of the x-axis and g : SURFACE waviness(according to JIS B 0610). Ra magnification is the value obtained with the formula on 0 X Note: Items other than a and f are added as necessary. the right is expressed in micrometer Reference:The location of lay of e in Fig. given as the finish allowance in ISO 1302.

3 R (Om)when y=f(a) . Symbol Meaning Figure IExamples indicating SURFACE texture on drawing Maximum peak(Ry) r Indicating symbol of SURFACE m Parallel to the projected SURFACE on A section of standard length is sampled from the mean line on the which the direction of lay of the roughness chart. The distance between the peaks and valleys of the Rp Ry cutting blade is indicated. sampled line is measured in the y direction. The value is expressed (ex) Shaped SURFACE Direction of lay in micrometer(Om) . Rv of cutting blade Indicating symbol of SURFACE requiring removal press Note:To obtain Ry, sample only the standard length. The part, where peaks and valleys are wide enough to be interpreted as scratches, should be avoided. Ry=Rp+Rv Perpendicular to the projected surfa- Ten-point mean roughness(Rz) m ce on which the direction of lay of the Indicating symbol of SURFACE on which no removal process is permitted Yp 1.

4 Yp4. cutting blade is indicated. Yp 2. A section of standard length is sampled from the mean line on the Yp 5. roughness chart. The distance between the peaks and valleys of the Yp 3 (ex)Shaped SURFACE ( when viewed Direction of lay Y V3. of cutting blade Y V2. from the side), machined or cyli- Y V1. Y V4. Y V5. sampled line is measured in the y direction. r ndrical ground SURFACE . Then, the average peak is obtained among 5 tallest peaks(Yp) , as is the average valley between 5 lowest valleys(Yv). Examples indicating the upper limits of Ra Yp1+Yp2+Yp3+Yp4+Yp 5 + Yv1+Yv 2+Yv 3+Yv 4+Yv 5. The sum of these two values is expressed in micrometer(Om). Rz= Intersection of two diagonal lines on the 5 (a) (b) (c). projected SURFACE on which the direction of Yp1, Yp2, Yp3, Yp4, Yp5: Tallest 5 peaks within sample lay of the cutting blade is indicated. 25 25. Honing finished SURFACE (ex) Direction of lay Yv1, Yv2, Yv3, Yv4, Yv5: Lowest 5 peaks within sample of cutting blade 25 25.

5 Multidirectional intersection or non- directional point on the projected SURFACE Reference:Relationship between arithmetical mean roughness(Ra)and conventional symbols on which the direction of lay of the Standard length cutting blade is indicated. Examples indicating direction of lay Arithmetical mean roughness Max. height Ten-point mean roughness Triangular Ra Ry Rz of RyCRz (ex)Rapping finished SURFACE , super indication Preferred number series Cut-off value Indication of SURFACE texture on drawings Preferred number series r (mm) finished SURFACE , face milled or end c(mm). milled SURFACE in surfacing feed a s z direction a s z ~ a s z Concentric circles roughly centered Examples indicating the upper limit and lower limit of Ra a s z on the same on the SURFACE on which a s z (a) (b). the direction of lay of the cutting a s z blade is indicated. a ~ s z (ex) Facing SURFACE a s z a s z ~ a 25 s 25 z Radiating shape roughly centered Examples indicating processing method a 50 s 50 z on the same point on the SURFACE ~ 25 (a) (b).

6 25 a 8 100 s 100 z on which the direction of lay of the 8 cutting blade is indicated. Front milled M. 50 a 200 s 200 z 50 ~ 100 ~. 100 a - 400 s 400 z - GThe interdependence for 3 classes is not strictly enforced. GThe evaluation length of Ra, Ry and Rz:Five times the cut-off value standard length respectively. 1167 1168.