Page 1657 - MiSUMi 2025

[Technical Data]
Drawing Indications of Surface Texture
Excerpts from JIS B 0031 (1994)

1. Positions of Auxiliary Symbols for Surface Symbol
A surface roughness value, cut-off value or reference length, machining method, grain direction, surface
undulation, etc. are indicated around the surface symbol as shown in Fig. 1 below.
Fig. 1 Positions of Auxiliary Symbols
a : Ra Value
b : Machining Method
b
f c : Cut-Off Value, Evaluation Length
a c c'
e d g e d g c' : Reference Length, Evaluation Length
d : Grain Direction
f : Parameter other than Ra (tp: Parameter / Cut-Off Level)
g : Surface Undulation (JIS B 0610)
Reference These symbols except a and f are provided when they are needed.
Reference Under ISO 1302, a finish range should be indicated as e in Fig. 1.
Q Examples of Graphical
Code Meaning Illustration
Representation of Surface
Texture
The trace left by a cutting tool is
parallel to the projection plane in Surface Symbol
the drawing.
Ex. Shaped Surface
Trace Left by
a Cutting Tool
Removal of Material by Machining is required
The trace left by a cutting tool is
perpendicular to the projection
plane in the drawing.
Ex. Shaped Surface (Side
View) Circular Cut, Trace Left by
Cylindrical Cut a Cutting Tool Removal of Material is Prohibited

The pattern left by a cutting tool
diagonally crosses the projection
plane in the drawing.
Ex. Honed Surface Upper Limit of Ra
Trace Left by (a) 25 25 (b) 6.3 6.3 (c) 25 25
6.3
25
25
a Cutting Tool 25 25 6.3 6.3 25 25
25 25 6.3 6.3 25 25
25
25
25
6.3
25
6.3
The pattern left by a cutting tool 25 25 6.3 6.3 25 25
crosses in various directions or 25 25 6.3 6.3 25 25
has no grain direction. 25 6.3 25
Ex. Lapped Surface,
Superfinished Surface Grain Direction
and Surface Finished
with a Front Mill or End
Mill
The pattern left by a cutting tool
is virtually concentric around Upper and Lower Limits of Ra
the center of the plane in the
drawing. (a) (b)
6.3
Ex. Faced Surface 6.3 6.3
6.3 1.6
1.6
1.6
6.3
1.6
6.3 1.6 6.3
6.3
6.3
1.6 1.6 6.3 6.3
1.6
1.6
1.6
1.6
6.3 6.3
1.6
6.3
The pattern left by a cutting 1.6 1.6
tool is virtually radial around Machining Method
the center of the plane in the (a) (b)
drawing. Milled Milled M M M
Milled
3.2 Milled
3.2 M
3.2
3.2 Milled 3.2 M 3.2
3.2 Milled 3.2 M 3.2 M
3.2 Milled
3.2 3.2 3.2 3.2 B-012