Sheet Metal And Non-Metalic Structures Flashcards
How do you determine the total lenght 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 remaning projecting part is trimmed flush with the head.
Give examples self plugging mechanical lock rivets.
CherryLOCK, CherryMAX, CherrySST, HulkLOCK and OLYMPIC-LOCK.
What methods are used in forming sheet metal?
Shrinking, Stretching, Bumping, Crimping, 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/corner.
What is a joggle?
It’s the offset formed on a part to allow clerance for a sheet or another mating part.
What is the purpose of lightning holes cut in rib sections?
To reduce weight and increase off stiffness.
Describe rivet head markings for A,B,D,AD and DD rivets:
A - Are Plain
B - Have a Cross
D - Have a Raised Dot
AD - Have a Dimple
DD - Have a double dash.
What are the correct dimensions on a properly formed rivet head.(shop head)
1 ½ the shank diameter and ½ the shank of diameter hight.
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 used in the original structure.
What is the single row spacing and edge distance for protunding 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. requirements.
For 5/32 or less diameter, use the next larger size rivet 2117 and the edge/spacing distance meet the minimum
What is the major type of damage to aluminum structures that is caused by exposure to the weather?
Corrosion
What is the difference between the tools required to pull a CherryLOCK rivet and a CherryMAX rivet?
CherryLOCK - Require a different tool for each rivet size.
CherryMAX - Same tool for all.
How can a mechanic determine whether the countersink for a flush rivet should be dimpled or drilled?
By the thickness of the top sheet, thin sheets are dimpled and thick sheets may be 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?
Bucking bar too large or heavy - Difficult to control and you can damage the sheet metal.
Bucking bar too light - Will not properly upset the rivet before work hardening occur.
What procedures should be followed to properly remove a solid-shank rivet?
Center punch the rivet and drill to the base of the rivet head using the same size oro ne size small drill, then use a pin punch to tip off the rivet head.
Which of the five stresses is the most common cause of rivet failure?
Shear
