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What are MS (Military Standard) and NAS (National Aerospace Standard) bolts known for?
High strength and aviation-grade precision
What type of tensile strength do MS & NAS high-strength bolts typically have?
Very high
Internal wrenching bolts are designed to be installed using which tool?
Allen wrench / hex socket
Internal wrenching bolts are known for having what level of tensile strength?
Very high
Which statement about the MS20073 bolt is correct?
A. It has coarse threads
B. It has fine threads
C. It has no threads
D. It is a countersunk bolt
It has fine threads
Which statement about the MS20074 bolt is correct?
A. It has fine threads
B. It has coarse threads
C. It has drilled flats
D. It is a Phillips-head bolt
Answer: B. It has coarse threads
On MS drilled-head bolts, where are the holes located?
Drilled through every flat of the bolt head
What is the purpose of countersunk head bolts?
To allow flush installation
What tools can be used to install countersunk head bolts?
Phillips screwdriver & Allen (hex) wrench
What are the two most common types of washers used in aircraft installations?
AN960 and AN970
Which of the following is NOT a purpose of a washer in aircraft installation?
Increasing bolt tensile strength
Why is a plain washer used under a lock washer?
To prevent damage to the surface
washers are manufactured in which two thickness types?
Regular and thin (half thickness)
What does the dash after AN960 indicate?
Material type
What does the letter “C” mean in AN960C?
Stainless steel washer
What does the number after AN960 specify?
Bolt size the washer fits
AN960-616 would be used with which bolt size?
6/16" or 3/8"
What does the “L” represent in AN960-6L?
Thin/light washer
AN970 washers are primarily used for what material?
Wood
Why does the AN970 washer have a larger surface area?
To protect wood by spreading the load
What is another common name for the AN970 washer?
Penny washer
Which of the following is NOT a type of lock washer mentioned?
Star-wing washer