Metal Structure Repair Questions
What is generally the best procedure to use when removing a solid shank rivet?
Drill to the base of the manufactured rivet head with a drill one size smaller than the rivet shank and remove the rivet with a punch.
A sheet metal repair is to be made using two pieces of 0.0625-inch aluminum riveted together. All rivet holes are drilled for 1/8-inch rivets. The length of the rivets to be used will be
Each of the two sheets of material to be riveted together has a thickness of 0.0625 inch. The total thickness of the material is 0.125 inch, and the 1/8-inch rivets should extend through the material for 1-1/2 diameters, which is 0.1875 inch. The total length of the rivet must be 0.3125 inch, which is 5/16 inch.
Select the alternative which best describes the function of the flute section of a twist drill.
Forms the cutting edges of the drill point.
What is indicated by a black 'smoky' residue streaming back from some of the rivets on an aircraft?
Fretting corrosion is occurring between the rivets and the skin.
The aluminum alloys used in aircraft construction are usually hardened by which method?
Heat treatment.
Which statement is true regarding the inspection of a stressed skin metal wing assembly known to have been critically loaded?
If genuine rivet tipping has occurred, groups of consecutive rivet heads will be tipped in the same direction.
The sight line on a sheet metal flat layout to be bent in a cornice or box brake is measured and marked
One radius from the bend tangent line that is placed under the brake.
When riveting dissimilar metals together, what precautions must be taken to prevent an electrolytic action?
Place a protective separator between areas of potential electrical difference.
Which of the following need not be considered when determining minimum rivet spacing?
Rivet length.
What type loads cause the most rivet failures?
Shear.
The dimensions of an MS20430AD-4-8 rivet are
1/8 inch in diameter and 1/2 inch long.
What should be the included angle of a twist drill for hard metal?
118°.
A single-lap sheet splice is to be used to repair a section of damaged aluminum skin. If a double row of 1/8-inch rivets is used, the minimum allowable overlap will be
13/16 inch
When drilling stainless steel, the drill used should have an included angle of
140° and turn at a low speed.
A piece of flat stock that is to be bent to a closed angle of 15° must be bent through an angle of
165°.
Which rivet may be used as received without further treatment?
2117-T3.
Which rivet is used for riveting magnesium alloy structures?
5056 aluminum.
How many MS20470 AD-4-6 rivets will be required to attach a 10 x 5 inch plate, using a single row of rivets, minimum edge distance, and 4D spacing?
56
What should be the included angle of a twist drill for soft metals?
90°
number of locking collar groves
A main difference between lockbolt/huckbolt tension and shear fasteners (other than their application) is in the
shear loads
A well-designed rivet joint will subject the rivets to
Which is correct concerning the use of a file?
Apply pressure on the forward stroke, only, except when filing very soft metals such as lead or aluminum.
The flat layout or blank length of a piece of metal from which a simple L-shaped bracket 3 inches by 1 inch is to be bent depends upon the radius of the desired bend. The bracket which will require the greatest amount of material is one which has a bend radius of
The larger the bend radius in this L-shaped bracket, the less material is needed. If we assume a metal thickness of 0.063 inch, the bracket having a 1/8-inch bend radius will need 3.865 inches of material. The bracket having a 1/2-inch radius will need only 3.704 inches of material. The bracket having a 1/4-inch radius will need 3.811 inches of material.
The primary alloying agent of 2024-T3 is indicated by the number
The primary alloying agent in 2024-T3 aluminum alloy is copper, which is identified by the first digit 2.
The length of a rivet to be used to join a sheet of .032-inch and .064-inch aluminum alloy should be equal to
The rivet length used to join two sheets of metal should be equal to the total thickness of the metal being joined, plus 1-1/2 times the diameter of the rivet. The total thickness of the material being joined is 0.096 inch. The length of the rivet should be 1-1/2 times the rivet diameter plus 0.096 inch.
Which rivets should be selected to join two sheets of .032-inch aluminum?
The two pieces of material to be joined have a total thickness of 0.064 inch. The rivet used with this metal should have a diameter of about three times the thickness of the thickest sheet. This would cause us to choose a rivet with a diameter of 3 x 0.032 inch, or 0.096 inch. The closest rivet to this is one with a diameter of 1/8 inch (0.125 inch). A 1/8-inch rivet should extend through the material for 3/16 inch, or 0.1875 inch. The total length of the rivet must be 0.064 + 0.1875, or 0.2515 inch. We would choose an MS20470AD-4-4 rivet. This is a universal head rivet, 1/8 inch in diameter and 1/4 inch long.
The length of rivet to be chosen when making a structural repair that involves the joining of 0.032-inch and 0.064-inch aluminum sheet, drilled with a No. 30 drill, is
The two sheets of material to be riveted together have a total thickness of 0.096 inch. The rivet installed in a No. 30 hole is a 1/8-inch rivet. It should extend through the material a distance of 0.1875 inch. The total length of the rivet must be 0.096 + 0.1875 = 0.2835. The nearest standard rivet length to this is 5/16 inch (0.3125 inch).
What is one of the determining factors which permits machine countersinking when flush riveting?
Thickness of the material is greater than the thickness of the rivet head.
A sheet metal repair is to be made using two pieces of 0.040-inch aluminum riveted together. All rivet holes are drilled for 3/32-inch rivets. The length of the rivets to be used will be
This problem calls for joining two pieces of 0.040-inch material, using 3/32-inch rivets. The total thickness of the material is 0.080 inch. The rivet should protrude through the material for 1-1/2 diameters, or 0.1406 inch (9/64 inch). The total length of the rivet must be 0.080 + 0.1406, or 0.2206 inch. The nearest standard rivet to this length is 1/4 inch long (0.250 inch).
What is the minimum spacing for a single row of aircraft rivets?
Three times the diameter of the rivet shank.
What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treatment?
To retard age hardening.
Which procedure is correct when using a reamer to finish a drilled hole to the correct size?
Turn the reamer only in the cutting direction.
If a streamline cover plate is to be hand formed using a form block, a piece of dead soft aluminum should first be placed over the hollow portion of the mold and securely fastened in place. The bumping operation should be
When using the bumping operation to form a compound curve in a piece of soft aluminum, use light blows of the mallet to work the material down gradually from the edges. Remember that the object of the bumping process is to work the material into shape by stretching it, rather than by forcing it into the form with heavy blows. Always start bumping near the edge of the form. Never start in the center.
Which part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture?
Which part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture?
The installation of Cherrymax and Olympic-Lok rivets is accomplished by utilizing
a pulling tool
The purpose of a joggle is to
allow clearance for a sheet or an extrusion.
MS20426AD-6-5 indicates a countersunk rivet which has
an overall length of 5/16 inch.
Clad aluminum alloys are used in aircraft because they
are less subject to corrosion than uncoated aluminum alloys.
Threaded rivets (rivnuts) are commonly used to
attach parts or components with screws to sheet metal
A piece of sheet metal is bent to a certain radius. The curvature of the bend is referred to as the
bend radius.
The marking on the head of a Dzus fastener identify the
body diameter, type of head, and length of the fastener
Shallow scratches in sheet metal may be repaired by
burnishing
Alloy 2117 rivets are heat treated
by the manufacturer and do not require heat treatment before being driven
Rivet pitch is the distance between the
centers of adjacent rivets in the same row.
Rivet gauge, or transverse pitch is the distance between the
centers of rivets in adjacent rows.
A factor which determines the minimum space between rivets is the
diameter of the rivets being used.
Most rivets used in aircraft construction have
dimples.
If it is necessary to compute a bend allowance problem and bend allowance tables are not available, the neutral axis of the bend can be
found by adding approximately one-half of the stock thickness to the bend radius.
A rivet set used to drive MS20470 rivets should
have a slightly greater radius than the rivet head.
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud length is measured in
hundredths of an inch
Unless otherwise specified, the radius of a bend is the
inside radius of the metal being formed.
Under certain conditions, type A rivets are not used because of their
low strength characteristics.
When comparing the machining techniques for stainless steel sheet material to those for aluminum alloy sheet, it is normally considered good practice to drill the stainless steel at a
lower speed with more pressure applied to the drill
The sharpest bend that can be placed in a piece of metal without critically weakening the part is called the
minimum radius of bend.
Metal fasteners used with carbon/graphite composite structures
must be constructed of material such as titanium or corrosion resistant steel
Heat-treated rivets in the D and DD series that are not driven within the prescribed time after heat treatment or removal from refrigeration
must be reheat treated before use.
When bending metal, the material on the outside of the curve stretches while the material on the inside of the curve compresses. That part of the material which is not affected by either stress is the
neutral line.
The shop head of a rivet should be
one and one-half times the diameter of the rivet shank
When an MS20470D rivet is installed, its full shear strength is obtained
only after a period of age hardening.
Repairs or splices involving stringers on the lower surface of stressed skin metal wings are usually
permitted but are normally more critical in reference to strength in tension than similar repairs to the upper surface.
Hole filling fasteners (for example, MS20470 rivets) should not be used in composite structures primarily because of the
possibility of causing delamination
The most important factors needed to make a flat pattern layout are
radius, thickness, and degree of bend.
Aircraft structural units, such as spars, engine supports, etc., which have been built up from sheet metal, are normally
repairable, using approved methods.
Parts fabricated from Alclad 2024-T3 aluminum sheet stock must have all
scratches, kinks, tool marks, nicks, etc., must be held to a minimum.
Joggles in removed rivet shanks would indicate partial
shear failure.
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud diameter is measured in
sixteenths of an inch
A DD rivet is heat treated before use to
soften to facilitate riveting.
The identifying marks on the heads of aluminum alloy rivets indicate the
specific alloy used in the manufacture of the rivets.
Mild steel rivets are used for riveting
steel parts.
When straightening members made of 2024-T4, you should
straighten cold and reinforce.
On a sheet metal fitting layout with a single bend, allow for stretching by
subtracting the setback from both legs.
You can distinguish between aluminum and aluminum alloy by
testing with a 10 percent solution of caustic soda.
When a piece of aluminum alloy is to be bent using a minimum radius for the type and thickness of material,
the layout should be made so that the bend will be 90° to the grain of the sheet.
When repairing a small hole on a metal stressed skin, the major consideration in the design of the patch should be
the shear strength of the riveted joint.
One of the main advantages of hi-lok type fasteners over early generations is that
they can be installed with ordinary hand tools
The general rule for finding the proper rivet diameter is
three times the thickness of the thickest sheet
What is the minimum edge distance for aircraft rivets?
two times the diameter of the rivet shank.
Which rivet is used for riveting nickel-steel alloys?
Monel.
