Mechanical drawing. Elementary and advanced (1910)
Reid, John S. (John Simpson), 1856- · New York, J. Wiley & sons; [etc, etc.] · leaf 251
thread in which the top and bottom of eachthread are made semicircular, as shown in Fig. 379. This formof thread is used for rough work and can be readily thrownin and out of gear with a portion of a nut. The Buttress Screw-thread is a combination of the Vand square threads, one side being… … Fig. 319. thread equal to ■§• of the total depth of the thread, as shownin Fig. 320. This form of thread can be used only when thepressure is on that side of the thread which is at right anglesto the axis of the screw.
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten10unit-641-440.webp)
