Module 7.8 Flashcards
Where must rivets not be used for?
-tensile force area
-not on thick materials
How is an air/water tight seal achieved?
Use sealant
What are 3 types of riveted joints?
-lap
-flush
-joggle
Are lap joints aerodynamically smooth?
No they’re not aerodynamic
When would a flush joint be used?
Aerodynamic structure that needs to be streamlined
In a flush patch repair what is the patch secured to?
A doubler
What are the two uses of a joggle joint?
-combination of flush and lap to produce a flush side
-fitting doublers over internal structures
What is the pitch of a rivet?
Distance between two adjacent rivets
What is the difference between edge margin and edge distance?
-edge distance is from the edge of the hole to the edge of the sheet
-edge margin is centre of hole to edge of sheet
What’s rivet spacing?
Distance between fastener rows (4-5D)
What’s the sphere of influence?
Area of sheet metal over which a rivet achieves a water tight seal (5D usually)
When would you use a rivet cutter?
When you don’t have access to the correct size rivet
What are bucking bars and what is important to consider when choosing one?
They’re used to deform the tail of the rivet.Choose the correct shape for the access you have.
Slow hitting rivet guns are most common.What is the range in operating speed?
900-2500 blows per minute
When selecting a rivet header what should you ensure?
Correct header,correct size, dome for universal
When can compression riveting be used?
Access to both sides.Hand held and riveting
What are the two types of squeeze rivet jaws?
Yoke and alligator yoke
How do you hold two sheets of material together for riveting?
-skin pins
-cleco pins
-gripper pins
When would you use a rivet shaver?
When you need to shave down the mandrill of blind rivets or on countersunk rivets if permitted
What are two methods of countersinking and what’s the most common angle?
-freehand
-microstop
At 100 degrees
When would you dimple?
Material too thin to countersink. Knife edges are stress rousers.
What are the 3 methods of dimpling?
-coin dimpling
-radius dimpling
-hot dimpling
If replacing a rivet due to damage or misforming what must be done?
1/32 larger diameter
If the snap head is too big what occurs?too small?not placed correct?
-too big damaged skin
-too small damaged rivet head
-not square damage rivet head and skin
Two types of misformed tails are?
Dragged or stepped
What are some unacceptable types of rivet forming?
-dragged or stepped rivet
-shanked rivet
-part gap
-tail cracks
-bell shape tail
How should the size of a formed rivet tail be checked?
Go/no go gauge
