M6 V2 Flashcards
1
Q
A load that is uniformly distributed over a certain area and also the per unit of area expressed is PSI
A
Unit stress or stress
2
Q
A kind of stress that results in the tending to stretch or lengthen the material
A
Tensile Stress
3
Q
A force that compresses or shortens the material
A
Compressive stress
4
Q
A force that results two metal riveted to each other which causes sliding motion or shear
A
Shearing stress
5
Q
A force that twists the material.
A
Torsion Stress
6
Q
The relations between external forces applied to an elastic body and the deformations and internal stresses resulting from those applied forces
A
Strength of Material
7
Q
Ability of a material to be stretched and go back to its original state or recover
A
Elasticity
8
Q
When the stress on the area is a combination of tensile, compressive, shearing, twisting
A
Combined Stress
9
Q
When a single stress alone is considered to act
A
Simple Stress
10
Q
The ratio of a lateral strain to longitudinal unit strain for a given material
A
Poisson’s Ratio
11
Q
The maximum stress that can be applied to a material without permanent deformation
A
Yield strength
12
Q
The stress at which a material in tension, compression, or shear will fracture
A
Ultimate Strength
13
Q
The ratio of stress to strain, within the proportional limit of a material in tension or compression or the amount of deformation.
A
Modulus of Elasticity
14
Q
Enables a material to resist penetration, wear, or cutting action
A
Hardness
15
Q
Ability of a material to withstand forces which tend to deform or the ability of a material to resist stress without breaking
A
Strength
16
Q
Ability of a material to be stretched and go back to its original state or recover
A
Elasticity
17
Q
The property of metal which allows it to be reshaped.
A
Plasticity
18
Q
The ability of a metal to be drawn into thinner sections without breaking and can resist deformation in tension
A
Ductility
19
Q
The ability of a material that allows it to be stretched o shaped by beating with a hammer or passing through rollers and can resist deformation through compression
A
Malleability
20
Q
The property of a material that allows it to be deformed without breaking
A
Toughness
21
Q
Ability of a metal to break when deformed or hammered. It is the resistance to change in the relative position of molecules within the material
A
Brittleness
22
Q
Ability of a material that makes it possible for it to transmit heat or electrical conduction
A
Conductivity
23
Q
Ability of a material that enables it to withstand force over a period of time
A
Durability
24
Q
Number of metals used in applications in technical fields
A
70 metals (chemical elements)
25
Density of airframe constructions light weight metals in kg/dm3
Less than 5
26
On a/c structures, Density of heavy weight metals in kg/dm3
Between 7.85 and 9.5
27
Method that uses diamond tip to get the depth
Rockwell test
28
Method that uses a steel ball to get the area
Brinell test
29
A rigid body in which the constituent particles are arranged in a repeating pattern.
Crystal
30
Known as the basic building block of a crystal
Unit cell
31
A unit cell that has a total of 9 atoms
Body-Centered-Cubic (BCC)
32
A unit cell that has a total of 14 atoms
Face-Centered-Cubic (FCC)
i) Examples are Cu, Au, Ni, Ag, Fe
33
A unit cell that has a total of 17 atoms.
Hexagonal-Closed-Packed (HCP)
Examples are Co, Mg, Ti, Zn
34
The selection of materials should be the best compromise between the________ to fulfill the requested functions and all cost at the time of aircraft development
quality of the material
35
The base material Iron in its pure form is __.
Very soft, malleable, easy to form and shape
36
Main restriction of steel is because of
a) high density >7.85 kg/dm3 (3x the density of Al) and susceptibility to corrosion
b) can increase corrosion resistance by adding alloying agents
37
Application of steel in an aircraft
Between 8 and 16 % (Airbus 320: 9%, Boeing 777: 11%)
38
Primary advantages of high-strength steels
High strength and high modulus of elasticity
39
Steel composition
Iron and Carbon
40
Iron is extracted from
Iron ore > Pig iron (raw material of steel)
41
Letter used for “Structural Steel” according to EN 10027 standard
S
42
Letter used for “Mechanical Engineering Steels” or german word “Einsatzstahl” (case hardening steel)
E
43
HHT steel that is the common steel alloy for use in the 180-200 ksi range
4130
44
HHT steel that has a strength range of 200 ksi up to 280 ksi and commonly used in 260-280 ksi range
4340
45
HHT steel that is commonly used is landing gear components and has 240-290 ksi range
300M
46
A process that increases the yield strength by temperature depending solution of aluminum atoms within the iron-crystal
Precipitation Hardening (PH)
47
Small surface damage such as scratches, nicks, or corrosion, localized stress concentration
Notch Sensitivity
48
Occurs when low- alloyed steel are deformed chip less in the cold state.
Cold Shortness Sensitivity
49
An accidental application of heat such as mechanical processing/ overheating during flight, may lead to structural changes and loss of stability
Temperature Sensitivity
50
Any wetting with acidic fluids or Mordants can lead to
Hydrogen Embrittlement
51
Heat treated steels may NEVER be welded or heat
straightened or their structure will RESHAPE
52
Applicable for steel components, which are hardened and have to be softened for mechanical processing, also called the zero state
Soft Annealing (becomes austenite: soft and ductile) – after
heat treatment
53
Serve for structure refinement and releasing internal stresses in the component. Reduces stress and strain before machining
Normalizing and Stress Relief Annealing
54
High alloy steel, >5%.
Demands resistance to high temp corrosion
55
Cres 14-4-ph
_% chromium-_% nickel – precipitation hardening
56
Increases the yield strength by temperature depending solution
of aluminum atoms within the iron-crystal
PH- precipitation hardening
57
Stainless steels are treated on when in contact with lightweight alloys and the protection is for the other material not the stainless steel.
Surface protection- sacrificial metal layer
i) Stainless steel- to avoid galvanic corrosion
ii) Non-stainless steel- painting, AL spraying
58
Used in aerospace industry because of light weight, high strength, heat resistant, corrosion resistant and has approximately 56% of the density of steal
a) Titanium
i) Density 4.5 kg/dm3 450degC
ii)Poor heat conductor
(1) Advantages: low weight, high strength (+alloying agent), high corrosion resistant, low thermal conductivity, good heat resistance (sensitive to hydrogen embrittlement)
(2) Not castable. Can only be welded by inert gas or vacuum
(3) In A/c construction STR rivets air ducts /ENG fan area
59
Tensile strength of pure aluminum is
Between 80 up to 600 N/mm
60
Most important titanium alloy in aircraft construction
Ti6Al4V
61
Most common alloying element of Titanium
Aluminum
62
When Titanium is exposed to temperature above 450o it must be protected from the atmosphere. Contact with media which releases hydrogen is dangerous for titanium, especially when heated above 150oC because this leads to
Hydrogen Embrittlement.
63
Heat resistance of titanium alloy when used in compressor blades
520 degrees Celcius
64
This metal is three times lighter than steel and has a melting point of 660degC
a) Aluminum 2.7 kg/dm3 660degC
b) one pound has more than twice the electrical conductivity of
copper
c) pure form high resistance but soft, if hardend resistance decrease
65
Good resistance against external damage
Non-hardenable AL Alloy
66
The strength depends on the alloy content and can be increased by_.
Strain Hardening
67
Can be heat treated to increase strength
Hardenable AL Alloy
68
A process that means to permanently weld metals layers onto a basis material, whilst applying high pressure. For corrosion protection
Cladding
i) Clad thin layer of pure aluminum
ii) ALCLAD / CLAD
69
Thickness of clad layers
3-5%(sheets with thickness that exceeds 6mm are not catalyst, which cladded)
70
Aluminum alloy that undergoes natural aging
2024( solidifies in 3-8 days, after 8 hrs, 90% of strength is achieved)
71
Aluminum alloy that undergoes artificial aging and the temp is about
120-200oC
7075(solidifies in 6-7 hrs)
72
Quenching interval
a) 5-15 seconds
i) Water bath 20 to 38 deg C
73
State of material after quenching
W-state
74
Carried out in aluminum alloys to bring the material into the minimum state of hardness and strength, whilst achieving the maximum stretch
a) Soft Annealing(zero state and done between 400-454oC)
b) After soft annealing aluminum MAY NOT BE QUENCHED
75
AlCuMg-alloy in a soft annealed temper which is the 0-state
2024-0
76
AlCuMg-alloy in a hardened temper, and is solution annealed, quenched, strain hardened and naturally aged
2024-T3
77
AlZnCuMg-alloy in a hardened temper, and is solution annealed, quenched, and artificially aged
7075-T6
78
A layered composite material that is a member of a family of materials called FML. An is an optimized FML for aircraft and consist of alternating layers of aluminum and glass fibre prepreg layers
a) GLass Aluminum REinforced Laminate
i) Used on fuselage skin structures on A380, aircraft cargo bay floors and liners, aircraft cargo explosive resistant containers
79
Materials that consist of thin layers of metal sheet and unidirectional fibre layers embedded in an adhesive system
Fibre Metal Laminate(FML)
80
Thermoset is
Irreversible
81
Thermoplastic is
reversible by application of heat
82
Term used to describe two or more materials that are combined to form a much stronger structure than either material itself and is used mainly to reduce weight
a) Composite
i) ADVANTAGES
(1) To reduce weight
(2) High strength to weight ratio
(3) Reduction of parts and fastener
(4) Reduction of wear
(5) Corrosion resistance
ii) DISADVANTAGES
(1) Expensive
(2) Not easy to repair
(3) Hazardous
83
Longest thread with marking
Warp
84
Fibers that are already impregnated with resin in the production process and then cooled down very fast which start to cure when heat is applied.
Prepreg/ Pre-impregnated Fibres
85
Used to connect GFRP (resin – resin connection
Standard – Prepreg
86
Used to connect GFRP laminates with honeycombs or sheet metal parts
Bonding – Prepregs
87
Percentage of resin in and “Elitrex”
Prepreg
i) Standard
ii) Bonding
Resin content
i) Standard - 38%
ii) Bonding - 50%
88
During the curing process in an autoclave or in a heating press, 18-
20% of resin is pressed out
Resinflux
89
The third component of a composite structure
a) Core Material
i) Foam- filler material
ii) Honeycomb- excellent strength to weight ratio
90
A process which the bonding of honeycomb is done one at a time
Corrugation process
91
A process which the bonding of honeycomb is done with all materials bonded simultaneously
Expansion process
92
Layers that build up a monolithic wall
5 layers
93
Layers that build up a honeycomb or sandwich
7 layers
94
A type of construction where a core material is the center member of the assembly
Sandwich construction
95
Used to bond two or more surfaces together. Used to distribute
stresses at bonding points and are moisture and corrosion resistant and eliminates the need for bolts and rivets
a) Adhesives
i) HOW TO KNOW IF ADHESIVE IS EFFECTIVE?
(1) Resistant to slippage, malleability, cohesive strength,
adhesion
96
Known as polymerization adhesives and used as a modifier of natural adhesives to perform better have a greater range of application
Synthetic adhesives
97
Synthetic adhesive or natural adhesives based on Silicon
Elastomeric Adhesives
98
Transformed into tough, heat resistant solids by the addition of catalyst or by application of heat e.g. epoxy resins
Thermosetting adhesives
99
Atmospheric pressure is used to press two solids together so there will be no air between the two plane parallel surface
Contact adhesives
100
Contains plastic and resins dissolved in a solvent
Solvent adhesives
101
Adhesives dissolved in water solution
Dispersion adhesives
102
Bonding of Same Material
Cohesive
103
Bonding of different material
Adhesive
104
Bonding substance of composite and most likely be liquid in form
Matrix
105
Resins that are best used in aircraft external structures. Used in high- tech composites because their mechanical properties are superior to those of polyesters
a) Epoxy resins
i) DISAVANTAGES
(1) TOXICITY (can cause dermatitis)
(2) LOW POT AND SHELF LIFE
(3) COST
106
Resin + hardener ratio
By volume
107
Adhesives that are best used inside the aircraft structures/cabin. Low toxicity
Phenolic Resins
108
Does not have the quality for structural components because it does not bond well to fibres
Polyester resin
109
The most important factor for bonding, and is frequently expressed with the contact angle that is formed between a droplet of a liquid and a solid
Surface wetting
110
Take into account that the adhesives must penetrate into the cavities before curing to prevent bubbles
Mechanical Hooking
111
The amount of time you have to work with the resins
Pot life
112
The time which the product is still good in an unopen container
Shelf Life
113
Too much resin is used and affects the strength of the composite by making the part brittle and add extra weight
Resin rich
114
Damage classification
a) Allowable
b) Repairable
c) Non repairable
115
Denomination of a process to abrade the bonding surfaces with a chemical treatment in order to enlarge the adhesive surface
Pickling
116
A result with a contact with a sharp object and only the surface of are affected and the edges are sharp
Scratch
117
Wider and deeper than a scratch, several plies are affected. But edges are generally smooth
Gouge
118
Gouge and scratch repaired by
Removing the damage plies and hand lay- up
119
Damage to a surface caused by scuffing, rubbing, or scraping of the component
Abrasion
120
When humidity penetrates a sandwich structure this happens
Corrosion on sandwich structures
121
Separation of materials or laminates due to adhesive failure
Debonding
122
Method used to detect water absorption
Non Destructive Testing (NDT)/ Thermograph
123
A deformity caused by extraneous forces, which are applied to the structure
Depression or Dent
124
Repair recommended for small damage on honeycomb materials and loses half of the material’s original strength
Filling repair
125
Consist of applying several layers of fabric material impregnated with a resin onto the repair surface, in order to restore the damaged skin.
Wet Lay – Up
126
it is used to consolidate the layers in the laminated repair, remove trapped air and gases produced during curing, hold heater blankets, thermocouples and other materials in place during the curing cycle and produce desired surface finish on the repair
Vacuum Bagging
127
Defines as an undesirable, natural reaction of materials with substances in their environments
a) Corrosion (derived from Latin word corrodere which means
“gnawing away”)
i) Influence Factors of Corrosion
(1) Type of metal
(2) Anode and cathode
(3) Temperature
(4) Presence of electrolyte
(5) Heat treatment
128
Occurs due to the tendency of most metals to return to their natural state by combining it with atmospheric oxygen
Corrosion of metals
129
______do not corrode since they are chemically pure.
Noble Metals such as gold and platinum
130
Corrosion on the surface grains of the metal because of its crystalline structure and happens at the boundaries between grains
Intercristalline corrosion
131
Material used as coating of a metal and used as anti-corrosion
pure aluminum coating (AlClad)
132
Preventive measures on corrosion
i) Steel requires cadmium plating, zinc plating and aluminum coating, etc.
ii) Aluminum alloys are usually anodized
iii) Magnesium and magnesium alloys requires special chemical and electrochemical treatments and paint
finishes.
133
The corrosion process that takes place at the surface of the electrode
under the influence of electrolyte and creates a half cell
Electrochemical Reaction
134
Consist of two half cells and a noble metal and a base metal, which serves as electrodes and are each in a sulfate solution
Galvanic cell
135
forming of oxide films/exposed from oxygen causes corrosion
Oxidation
136
Absorbing of electrons
Reduction
137
Oxidation Is Loss, Reduction Is Gain
OIL RIG
138
presence of aggressive chemical in the atmosphere/ without
ELECTROLYTE
Chemical corrosion
139
Electrically conductive fluid or moisture
Electrolyte
140
A galvanic dissolution that commonly occurs between adjacent components, whose metals have different electrochemical potential and under the influence of electrolyte
Electrochemical Corrosion
141
Also called the Microbes corrosion and is caused y a direct chemical attack of metabolic products of microorganisms
Biological corrosion
142
When mechanical forces act on a component which leads to corrosion
Stress corrosion
143
Corrosion color in steel
Red rust (hydrated ferric oxides)
144
Corrosion product on aluminum
White – grey powdery material
145
Special form of crevice corrosion which occurs on metals surface having an organic coating system and is identified by wormlike trace of corrosion
Filiform Corrosion
146
Corrosion that is a combination of stress and corrosion
Stress corrosion
147
Used as protection on titanium
Chromium acid anodize
148
Used as lubricant for fastener
a) Cetylalkohol
i) Most cathodic is Carbon
ii) Most anodic is Magnesium
149
Occurs when two dissimilar metals make electrical contact in the presence of an electrolyte
Galvanic Corrosion
150
The most common type of corrosion on aluminum and magnesium and appears a white powdery deposit and the starting point for intergranular corrosion
Pitting Corrosion
151
A corrosion on the grain boundaries of the metal and occurs when cladding is damaged
Intergranular Corrosion
152
Mostly seen on extruded sections, this advanced type of intergranular corrosion exhibits itself by lifting up the surface of a metal by force
Exfoliation Corrosion
153
Results in the rubbing movement between two heavily loaded surfaces and can eventually cause cracking fatigue
Fretting Corrosion
154
A corrosion cause by bacteria, fungi or yeast in an unclean fuel and looks like a sludge like deposit.
Microbial Corrosion
155
Necessary if a contamination of fuel tank is detected
Biocide (kathon or biobor)
156
Occurs between two materials that come into contact, metallic or non-metallic
a) Crevice Corrosion
i) Solid rivets are Self-sealing fasteners
ii) For shearing loads in fasteners small head is used for
weight saving
157
Fahrenheit to Celsius
a)
Celsius to Fahrenheit
a)
158
Used to attach components or assemblies to the aircraft structures
Fastener
159
used to attach high-strength components to the assemblies
aluminum solid rivets
160
used for joints in high-temp areas
steel, titanium or monel fasteners
161
If groove is formed on the external
Male thread
162
If groove is formed internal
Female Thread
163
Thread formed on a cylinder is known as
Straight or Parallel Thread
164
Thread formed and cut onto a conical part
Taper thread
165
thread with an angle of 55 degrees
British Standard Whitworth (BSW)
166
Finer version of the whitworth thread form and the smaller thread provides a finer form of adjustment and greater resistance to vibration in all fastening devices
British Standard Fine (BSF)
167
This is another fine-pitch adaptation of the whitworth thread form. It is used for pipeline couplings where the fine pitch ensures that sufficient uncut metal remains on the wall of a pipe to guarantee a strong connection
British Standard Pipe (BSP)
168
Has a thread angle of 47.5 degrees
British Association (BA)
169
They have a thread angle of 60 degrees
ANC and ANF (American National Coarse and Fine)
170
Incorporates features from both American and British ntnl threads
Unified
171
A screw that has a deeper thread and have fewer threads, greater lead
Coarse Pitch
172
A screw that have a stronger root portion, tighter grip and more resistant to shaking loose, strong against vibration,
Fine Pitch
173
Most common thread form and shaped to combine strength with ease of engagement
a) Vee Thread
i) Install bolts and screws foremost and uppermost
174
Install nuts not less than what of the bolt
1/32 in (0.8mm)
175
Torque values are at what manual
SRM ch51 or AMM
176
It is where the code marking of aircraft bolts are identified
a) Bolt head
i) NE = Long Thread
ii) NF= Short Thread
iii) Diameter of bolt is always in 1/16
iv) Diameter of Hi- Lok and Rivet is always 1/32
v) Grip Length is always 1/16
177
T> 2.4mm = max 2 thread pitches
178
T< 2.4mm = no thread pitches w/in the hole
179
Maximum of 3 washers may be used to adjust a grip length
(1 under the head, 2 under the nut)
180
A piece of rod, threaded at each end with a plain portion in the middle
Stud
181
A piece of a hexagonal metal bar, drilled and tapped through its axial center – line
Stud box
182
Used extensively to secure thin – gauge sheet metal parts where nuts and bolts are either impractical or too expensive
Self-Tapping Screws
183
Are used with drilled shank hex head bolts, clevis bolts, eye bolts and rivets and is designed to lock cotter pin or wirelocking
Non- Self Locking Nuts
Classifications:
➢ Shear Castle Nut – used only for shear load on clevis bolts
➢ Castle Nut- Are designed to fit on standard airframe bolts and
may be used when the bolt is subjected to either shear or tensile strength
➢ Slotted Engine Nut- designed for use on aircraft engine and is not approved for airframe use. Made of Heat- treated steel
➢ Wing Nut- intended for use on hose clamps and battery
connections where the desired tightness is ordinarily obtained by
the use of fingers
184
Locking nuts (5) not reuseable
➢ Lock nut- Is a thin, plain nut which is tightened down firmly
onto the main, plain nut.
*Nyloc Stiff nuts- has an unthreaded nylon insert permanently
housed at the outer end
➢ Oddie Stiff nuts-Have six tongues at their outer end which are
bent inwards to form a circle slightly less in diameter than the
minor diameter of the bold thread
➢ Aerotight and Philidas Stiffnuts- have slotted locking
extensions which are closed during manufacture to put the screwthread out of alignment
185
is used when a slight range of movement is necessary to ensure the
bolt can locate
Anchor Nuts / Floating type anchor nut
186
High- temp self- locking Nuts
temp self locking >121degC (250F)
187
Low- temp self- locking Nuts
temp self locking < 121degC (250F)
188
Permit each thread to adjust to the screw and assure full load
distribution throughout the entire length of the thread, Protection for soft material
Heli – Coil Inserts
189
A process of securing all aircraft bolts, nuts, screws, pins and other fasteners so that they do not work loose due to vibration
Safetying
190
Most positive and satisfactory method of safetying and is a method of wiring together two or more units in such a manner that any tendency of one to loosen is counteracted by the tightening of the wire
Wirelocking
191
Most common method of wire locking
Double - Twist Method
192
either a single coil or square section spring with sharp corners or a double coil spring.
Spring Washers
193
is a metal washer with two or more tabs, suitable for use with plain nuts. One tab is bent against one of the flats of the nut and the other is bent over an edge of the component or fitted into or hole machined in the component. Not reusable
Tab Washers
194
is a spring steel washer with slanting serrations on its internal or external circumferences
Shakeproof Washer
195
is a simple and secure, non-threaded fastener, allowing rapid installation and removal of parts without tooling
Pip pin
196
A single ball locates the pin, no positive
lock
Ring Pull Detent Pin
197
it is a instantaneous self locking, vibration resistant and easy application pin
Double Acting Steel Pin
198
designed so that it can be quickly inserted into the grommet by compression of the spring
Camloc Fasteners
199
It has 2 types which are the light duty that is used on box covers,
access hole covers and light weight fairing and the second type which is the heavy duty type which is used on cowling and heavy fairings
Dzus Fasteners
200
It consists of a receptacle , stud and cross pin. It has two types which is the fixed type and floating type
Airloc Fasteners
201
used to secure bolts, screws, nuts and pins
Cotter Pins
202
Given to a specially – shaped piece of metal that is used to transmit at considerable mechanical power from a shaft to hub
Keys
i) A. Taper Keys
➢ Hollow Saddle Key- is hollowed to fit the radius of the shaft
➢ Flat saddle key- is a rectangular or square section that is driven into a keyway in the hub and bears upon a flat on the shaft
➢ Gib headed key- is fitted into keyways which are machined partly in the shaft and partly in the hub. It is capable of transmitting a much greater driving load than the saddle type keys
➢ Feather key- is used when axial movement is required between the hub and the shaft
➢ Woodruff key- is made in the shape of a segment of a parallel sided disc similar to capital D. it is suitable for fitting to either parallel or taper shafts.
203
Deformed portion of the Rivet
Upset Head
i) Selection of correct Rivet diameter is at least 3 times the
thickness of the thickest sheet being joined
204
Used to attach aluminum alloy components where a low-strength rivet is sufficient to hold the load
Aluminum Alloy Rivets
205
Without heat treatment before use, are used in steel, titanium or aluminum alloy riveted assemblies
Monel Rivets
206
Are rivets with a cylindrical or a partial tapered shank. No heat treatment is necessary for this type of rivet
Titanium Rivets
207
a process which a rivet material have to be heat treated before using them in the manufacturing process
Solution Annealing( Annealed at 495o and quenched at 20o)
i) At -18o temperature rivets can be stored for up to 7 days
ii) At -20o temperature rivets can be stored for up to 20 days
208
the time between opening the furnace or removing the rivets from
the salt bath and the complete immersion of the load into the quenching medium
Quench Delay
209
The time, within which the rivets must be upset, at room temp. 25o
Maximum Handling Time
210
A tapered bolt with a threaded end and a self – locking nut and used in areas where a high fatigue performance is required
Taper – Lok
211
A combination of a rivet and a nut, resembling a hollow rivet with threads inside its shank
Rivnut
212
Combined thickness of the material to be joined
Grip Length
213
Heat treatment of Al. Rivets
Solution Annealing
- The material is annealed at 495 degrees for a certain time and after that it is quenched at 20 degrees cold water. The material can be deformed without high loads and crystal damage
- All rivets 3.1324, 2017,2017 A and 2024- alloys must be stored at -18 degrees. At this temperature, the rivets can be stored up to 7 days and at -20 degrees, it can be stored up to 20 days
214
Is a tapered bolt with a threaded end and a self locking nut. It also includes it’s own washer.
Taper lok fastener
215
The numbers are printed in
Light or dark green
216
They are label with white numbers
Red, black, or dark green wires
217
The current capacity of wires is directly dependent on the
Conductor material, the insulation, and wire size
218
There is a general rule for determining the socket side:
Sockets shall always be installed on the live part of the connector
219
Emitting of electrons
Oxidation
220
Tensile strength of pure titanium
Between 300 and 700 N/mm2
221
Can be distinguished into construction steels and carbon steels
Non alloyed steels
222
Used for aforementioned application on aircraft
Carbon steel
223
is hollowed to fit the radius of the shaft
Hollow Saddle Key
224
is a rectangular or square section that is driven into a keyway in the hub and bears upon a flat on the shaft
Flat saddle key-
225
is fitted into keyways which are machined partly in the shaft and partly in the hub. It is capable of transmitting a much greater driving load than the saddle type keys
Gib headed key-
226
is used when axial movement is required between the hub and the shaft
Feather key-
227
is made in the shape of a segment of a parallel sided disc similar to capital D. it is suitable for fitting to either parallel or taper shafts.
Woodruff key-
228
Is a thin, plain nut which is tightened down firmly onto the main, plain nut.
Lock nut-
229
has an unthreaded nylon insert permanently housed at the outer end
Nyloc Stiff nuts-
230
Have six tongues at their outer end which are
bent inwards to form a circle slightly less in diameter than the minor diameter of the bold thread
Oddie Stiff nuts
231
have slotted locking
extensions which are closed during manufacture to put the screwthread out of alignment
Aerotight and Philidas Stiffnuts-
