Sheet Metal and Non-Metallic Structures Flashcards
How do you determine the total length of a solid rivet for installation ?
The grip length +1.5 x the rivet diameter
What is done with the rivet head stem when a self plugging rivet is installed ?
The stem is pulled until it snaps off and the remaining projecting part is trimmed flush with the head
Give examples of self plugging mechanical lock rivets
Cherry Lock, Cherry Max, Cherry SST, Hulk Lock, Olympic Lock
What methods are used in forming sheet metal ?
Shrinking, Stretching, Crimping, Bumping, Folding
What factors are used to determine setback ?
Bend radius and material thickness
What calculation must be made when bending sheet metal ?
Bend allowance and setback
What must be done when two bends intersect to prevent cracking ?
Relief holes are drilled at the intersection
What is a joggle ?
Its the offset formed on a part to allow clearance for a sheet or another mating part
What is the purpose of lighting holes cut in the rib section ?
To reduce weight and increase stiffness
Describe rivet head markings for A, B, D, AD, DD rivets ?
A - Plain, B - Cross, D - Raised Dot, AD - Dimple, DD - Double Dash
What are the correct dimensions on a properly formed rivet head ?
1 1/2 of the shank diameter in width, 1/2 of the shank diameter in height
How do you determine the proper material to be used for a repair of an all metal aircraft ?
Use the same type and thickness of the material that was originally being used
What is the single row spacing and edge distance for protruding head rivets ?
Edge 2 x diameter, Spacing 3 x diameter
Describe the criteria for replacement of a 2024 rivet with a 2117 rivet for general repairs ?
5/32nd or less in diameter, use the next larger size 2117 rivet and the edge/spacing distance meets the minimum requirements
What is the difference between the tools required to pull a Cherry Lock rivet and a Cherry Max rivet ?
Cherry Lock - Require different tool for each size
Cherry Max - Same tool for all
How can a mechanic determine weather the countersink for a flush rivet should be dimpled or drilled ?
By the thickness of the top sheet, thin sheets are dimpled, thick sheets are countersunk
What action is taken to prevent cracks from forming while dimpling magnesium or some hard sheet metals ?
Hot dimpling equipment is used to preheat and soften the metal before the dimple is formed
What type of damage can occur when using a rivet set that does not properly fit the rivet ?
The rivet head and the sheet metal may be damaged
Why is it important to use the proper bucking bar when performing sheet metal riveting ?
Too large - Difficult to control and you can damage the sheet metal
Too small - Will not properly upset the rivet before work hardening occurs
What procedure should be followed to properly remove a solid shank rivet ?
Center the punch the rivet and drill to the base of the rivet head using the same size or one size small drill, then use a pin punch to tip off the rivet head
