installation and removal of fasteners Flashcards
What is elastic Limit
Elastic Limit is the maximum tension that an object can sustain and still return to its original shape and be fully functional
What is proof load
The proof load is the highest recommended tensile load for that fastener
What is yield point
Yield point is the point at which a fastener suffers permanent deformation (set) when a tensile load is applied
Tensile strength
The maximum tensile stress or load a fastener can support before fracture occurs
Shear strength
The amount of continuous shear force (not cyclic or fluctuating) that a fastener can withstand before breaking
What is pre load
A pre load on a fastener means tightening it with its elastic limit before hand in order to prepare it to accept the load
What is toughness
The resistance to fracture or the amount of energy a substance absorbs before it breaks
What is Hardness
Hardness is the ability of a material to resist penetration
what is malleability
malleability is when a material can be shaped or molded easily
what is Ductillity
Ductility is a measure of how much a material can be deformed or drawn before it breaks.
What is Compressive Stress
Compression is the force acting on all materials between the bolt head and the nut to
compress or shorten them
What is torque
Torque is the turning force set by the wrench on a fastener
what is elasticity
if a material has the ability to be stretched without deformation
What does Dilation mean?
Dilation means that the nut is stretched to a larger diameter, shifting the tensile load onto the tips of the threads
How can you overcome Nut Dilation
Nut dilation can be overcome by increasing the wall thickness of the nut
How is bolt tension produced?
By a nut rotating and advancing on the bolt threads
True or False: Coarse threaded bolts have greater strength but lower thread shear strength
False Coarse Threaded bolts have LOWER strength but GREATER shear strength
what are two things to know when using adapters
1: The adapter must be solid
2: the amount that you increase the distance between the wrench handle and the socket must be accounted for by decreasing your torque requirement
what are the parts of a hydraulic jacking tool
the Puller, Ram, Socket, Tommy bar
What is required in a stud to heat it?
A hole bored down the center of the stud
What is the most popular heating tool used today?
Induction Heaters as they are the quickest and most accurate
how is residual Preload determined?
Residual preload is determined by measuring the stud length before and after tensioning and again during months of operation.
what is the tolerance for a surface finish?
63-80 microinches
Apply Lubricant to the threads of a fastener does what?
Increases the clamp load compared to dry threads