AutoCAD and Its Applications Basics 2011 - (AutoCAD及其应用基础2011 -).pdf
文本预览下载声明
AutoCAD
and Its Applications R E F E R E N C E
B A S I C S M AT E R I A L S
Student Web Site
Drafting Symbols
Symbols provide a “common language” for drafters all over the world.
However, symbols are meaningful only if they are drawn according to relevant
standards or conventions. This document describes and illustrates common
dimensioning, GDT, architectural, piping, and electrical symbols.
Recommended ASME Dimensioning Symbols
The size of dimensioning symbols is consistent with text height. In the
following illustration, H = text height.
60°
1.5H H
Diameter Radius Spherical Spherical Controlled Places
Radius Diameter Radius or By
1.5H
90 °
2H H
0.8H
H
2 H H H
Symmetrical Shape Counterbore Spotface Countersink Square Shape
H 0.3H
1.5H
H
1.5H
H
0.6H 60°
0.3H
Arc Length
显示全部