Vocabulary
True or False
Bonuses
Identifying
Fill In The Blank
100
Define: Major & Minor Diameters
What is...
The largest diameters of a screw thread, both external and internal (major diameter)
The smallest diameters of a screw thread, both external and internal (minor diameter)
100
UNC (Unified National Coarse) means the thread will be coarse.
What is...
TRUE
100
Name an object that needs a fastener to function.
What is...
Furniture, Buildings, Car & Fishing parts, + More!
100
Identify the type of screw
What is...
Flat Head Screw
100
Definition of External Thread:
Threads located on the _______ of a part (such as those on a bolt).
What is...
Outside
200
Define: Crest and Root
What is...
Crest: The top point joining sides of a thread
Root: The bottom point joining sides of a thread
200
Left-handed threads spin clockwise.
What is...
FALSE
200
Name three Unified National Series
What is...
UNC (Unified National Coarse), UNF (Unified National Fine), and UNEF (Unified National Extra Fine)
200
Define No. 5
What is...
Pitch Diameter
200
Class #_ is known to have a relatively loose fit.
What is...
Class #1
300
Define: Axis
What is...
A longitudinal center line of the thread.
300
All threads are assumed to be right-handed.
What is...
TRUE (if a thread is left-handed, it will be specified at the end of the second line.
300
Name the three classes of fit
What is...
Class 1 (loose), Class 2 (medium), Class 3 (tight)
300
Define No. 2
What is...
Thread Angle
300
The angle that is measured between the tangent to the thread helix and a line parallel to the screw’s axis is the _____ angle.
What is...
Helix
400
Define: Depth of Thread
What is...
The distance between the crest and root of the thread, as measured at a right angle to the axis.
400
The "Worm Thread Form" is a type of Screw Thread Form.
What is...
TRUE
400
What are rivets?
What is...
Permanent fasteners (that can be made out of wrought iron or soft steel).
400
Identify the type of screw
What is...
Round Head Screw
400
It was not until ____ that the United States adopted the American Standard Thread.
What is...
1935
500
Define: Retaining Ring
What is...
Precision-engineered fasteners that limit axial movement/displacement (aka keeping an object from stretching/shrinking)
500
A self-locking ring (which is a type of retaining ring) requires grooves.
What is...
FALSE
They do not require grooves because they have such a strong hold against axial displacement
(when a force is applied to a circular object, causing the object to expand (tensile force) or shrink (compressive force).
500
What is the formula for finding the depth of thread?
What is...
Calculate the thread length:
UNC: 2 x D + 0.5
UNF: 1.5 x D + 0.5
Calculate Pitch:
Thread Length / Threads Per Inch = Pitch
Find D.O.T. :
.65 x Pitch
500
Define No. 9
What is...
Helix Angle
500
The Unified National Thread form has been the standard thread used in the United States, Canada, and the Great Britain since ____.
What is...
1948