METALLIC STRUCTURE

One of the main advantages of HI-LOK type fasteners over earlier generations is that. they can be removed and reused again. the squeezed on collar installation provides a more secure, tighter fit. they can be installed with ordinary hand tools.

A piece of flat stock that is to be bent to a closed angle of 15° must be bent through an angle of. 165°. 105°. 90°.

The aviation mechanic can distinguish between aluminum and aluminum alloy by. filing the metal. testing with an acetic acid solution. testing with a 10 percent solution of caustic soda.

(Refer to Figure 6.) Determine the dimensions of A, B, and C in the flat layout. Setback = .252 Bend allowance = .345. A = .748, B = 2.252, C = 2.004. A = .748, B = 1.496, C = 1.248. A = 1.252, B = 1.496, C = 1.752.

Alloy 2117 rivets are heat treated. by the manufacturer and do not require heat treatment before being driven. by the manufacturer but require reheat treatment before being driven. to a temperature of 910 to 930°F and quenched in cold water.

Cylinders used to transport and store acetylene. are pressure tested to 3,000 psi. are green in color. contain acetone.

Rivet gauge, or transverse pitch is the distance between the. centers of rivets in adjacent rows. centers of adjacent rivets in the same row. heads of rivets in the same row.

The shielding gases generally used in the Gas Tungsten Arc (GTA) welding of aluminum consist of. a mixture of nitrogen and carbon dioxide. nitrogen or hydrogen, or a mixture of nitrogen and hydrogen. helium or argon, or a mixture of helium and argon.

Engine mount members should preferably be repaired by using a. larger diameter tube with fishmouth and no rosette welds. larger diameter tube with fishmouth and rosette welds. smaller diameter tube with fishmouth and rosette welds.

Most rivets used in aircraft construction have. dimples. smooth heads without markings. a raised dot.

When straightening members made of 2024-T4, the aviation mechanic should. straighten cold and reinforce. straighten cold and anneal to remove stress. apply heat to the inside of the bend.

A resurfaced soldering iron cannot be used effectively until after the working face has been. fluxed. polished. tinned.

The most important factors needed to make a flat pattern layout are. radius, thickness, and mold line. radius, thickness, and degree of bend. the lengths of the legs (flat sections).

Which procedure is correct when using a reamer to finish a drilled hole to the correct size?. Turn the reamer in the cutting direction when enlarging the hole and in the opposite direction to remove from the hole. Turn the reamer only in the cutting direction. Apply considerable pressure on the reamer when starting the cut and reduce the pressure when finishing the cut.

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. 1/8 inch. 1/4 inch. 5/16 inch.

When drilling stainless steel, the drill used should have an included angle of. 90° and turn at a low speed. 118° and turn at a high speed. 140° and turn at a low speed.

(Refer to Figure 7.) What is dimension F? Setback at D = .095 Setback at E = .068 Bend allowance at D = .150 Bend allowance at E = .112. 4.836. 5.936. 5.738.

Why is it necessary to use flux in all silver soldering operations?. To chemically clean the base metal of oxide film. To prevent overheating of the base metal. To increase heat conductivity.

Threaded rivets (Rivnuts) are commonly used to. join two or more pieces of sheet metal where shear strength is desired. attach parts or components with screws to sheet metal. join two or more pieces of sheet metal where bearing strength is desired.

What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treatment?. To accelerate age hardening. To relieve internal stresses. To retard age hardening.

The installation of CherryMax and Olympic-Lok rivets is accomplished by utilizing. rivet gun, special rivet set, and bucking bar. a pulling tool. ordinary hand tools.

What is the minimum spacing for a single row of aircraft rivets?. Two times the diameter of the rivet shank. Three times the length of the rivet shank. Three times the diameter of the rivet shank.

The primary alloying agent of 2024-T3 is indicated by the number. 2. 20. 24.

Which statement concerning a welding process is true?. The inert-arc welding process uses an inert gas to protect the weld zone from the atmosphere. In the metallic-arc welding process, filler material, if needed, is provided by a separate metal rod of the proper material held in the arc. In the oxyacetylene welding process, the filler rod used for steel is covered with a thin coating of flux.

The aluminum alloys used in aircraft construction are usually hardened by which method?. Cold-working. Aging. Heat treatment.

Why should a carburizing flame be avoided when welding steel?. It removes the carbon content. It hardens the surface. A cold weld will result.

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. A smoother finish can be obtained by using a double-cut file than by using a single-cut file. The terms 'double-cut' and I 'second-cut' have the same meaning in reference to files.

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. 1/8 inch. 1/2 inch. 1/4 inch.

What is generally the best procedure to use when removing a solid shank rivet?. Drill through the manufactured head and shank with a shank size drill and remove the rivet with a punch. 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. Drill through the manufactured head and shank with a drill one size smaller than the rivet and remove the rivet with a punch.

Oxides form very rapidly when alloys or metals are hot. It is important, therefore, when welding aluminum to use a. solvent. filler. flux.