PRIN. OF DRAFTING AND SHOP DRAWINGS - OD1641 - LESSON 1/TASK 2
LESSON 1
DRAFTING AND SHOP DRAWING FUNDAMENTALS
TASK 2.
Describe drafting
instruments
and
the
fundamentals
of
geometric
construction.
CONDITIONS
Within a self-study environment and given the subcourse text, without assistance.
STANDARDS
Within one hour
REFERENCES
No supplementary references are needed for this task.
1.
Introduction
In task one of this subcourse, we covered orthographic projection and freehand
drafting. In this task, we will cover drafting instruments and the fundamentals of
2.
Drafting Instruments
In the following paragraphs, we will cover some of the drafting instruments that
may be encountered and used; however, we will not cover such common instruments as
a. Scales. Scales are used for linear measuring. The scale most commonly used by
a draftsman is one with its inches graduated into sixteen divisions, with each
division measuring one-sixteenth of an inch.
Figure 16 (on the following page)
shows part of a "16 to the inch" scale, together with some sample measurements.
Unlike a real scale, the scale in figure 16 has the first inch completely labeled
to help you become familiar with the different fractional values.
Measurements
more
20