Johnston, Philip Devereux, 1855- · New York, D. Williams Company · leaf 130
ed in the draughting room in drawing largescrews, straight lines being employed to show* thethreads, instead of the developed curves of the helix.This is done to economize in time. There are manyoccasions for drawing the true curves, therefore thedraughtsman nmst be familiar with the method. PLATE… … us. STANDARD THREAD. COMMON 0/r V THREAD.p. -
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
