Letter for Internal thread correct answers B
Letter of External thread correct answers A
The _____ ____ on an internal or external schematic thread symbol represents the
thread's minor diameter. The crest line represents the major diameter. correct answers
root line
The American National (N) and the Unified National (UN) thread forms include 3 graded
series ___, ____, ____ correct answers coarse, fine, and extra-fine
The angle between threads cut by the cutting tool and is 60 degrees? correct answers
Thread angle
The distance from the crest of one thread to the crest of an adjacent thread is called the
correct answers Thread's pitch
By definition, the lead of a single screw thread is equal to the ______ ____. The lead is
the distance a screw will advance when rotated ____ correct answers thread's pitch,
360 degrees
______ ______ are used where quick assembly is required. _____ _____ is composed
of two threads that advance a distance of 2 times the thread's pitch (2p) when rotated
360 degrees. A ____ _____ is composed of three threads that advance 3 times the
thread's pitch (3p) when rotated 360 degrees. correct answers
Given the following English thread note: ______ UNF indicates the thread's graded
series is fine (Unified National Fine), 2 indicates the class of fit (medium), and A
indicates the thread is external. correct answers 1/2-20 UNF-2A, 1/2 is the major
diameter, 20 is the threads per inch - the distance between the crests of adjacent
threads (pitch) is .05 (1/20)
On Metric thread notes, the letter ___ is followed by a numeric value which represents
the thread's major diameter. The major diameter is followed by the letter ___ which is
followed by a numeric value which represents the thread's pitch in millimeters correct
answers M, X
Given the following Metric thread note: _____ = ______. 2.5 is the ___, 30 = ____. The
tap drill diameter can be found in the list of preferred Metric thread sizes in the appendix
of the textbook or in publications that publish standard thread sizes and other technical