Mechanical Engineering Concepts

Readings MD 1

• A tachometer is a device used to measure accurately speed
• A negative allowance is the term used when a hole is smaller than the shaft, requiring pressure to assemble parts; it is also referred to as interference metail
• The laws of conservation of momentum and conservation of energy can be used to solve for the resulting velocity, when two elastic bodies collide
• Plasticity refers to the ability of a metal to be deformed considerably without rupture
• Ductility refers to permanent deformation or strain that may occur without fracture
• Kinematics is the science of motion that can be solved in terms of scalar or vector algebra
• Equilibrium is maintained in a system of forces in space after two equal and opposite collinear forces are added
• Babbitt is a metal that assists lubrication or is a lubricant in itself
• A dividing head is a mechanism that usually does the indexing in a machine tool
• All of these: flywheel, balance of wheel, and flywheel pulley equalize the energy exerted and the work done, thus preventing excessive or sudden changes of speed
• Percentage reduction of area is the smallest area at the point of rupture of a tensile specimen divided by the original area
• Linear impulse is the product of the resultant of all forces acting on a body and the time that the resultant acts
• Tool and die steel is not a structural class of steel
• Poisson's ratio is the ratio of lateral strain to longitudinal strain
• SAE 74XX is not associated with the grade of steel
• Poisson's ratio is a property of material which relates the lateral strain to the longitudinal strain
• Ultimate stress is the maximum stress to which a material may be subjected before failure occurs
• A hypoid gear is a special type of bevel gear
• The maximum safe center distance of sprockets should be 80 pitches, where very long center distance causes catenary tension in the chain
• Cold working of steel plates makes the metal harder
• The recommended best cutting angle of a drill for work on steel or cast iron is 59 degrees
• A breaking stress of 50 ksi can be used in shear pin or breaking pin design data from link belt for 1/8 inch to 1-inch pins
• Kinematics deals only with the motion of bodies without reference to the forces that cause them
• Ductility characterizes a material's ability to be drawn into a wire
• For spur gear tooth breakage, unbalanced load on one end of the tooth results in higher stresses and to minimize this problem, it is guided that 2.5 Pc < b < 4 Pc
• The three moment equation may be used to analyze a continuous beam
• Surrounding the work with clay is a common shop practice to prevent solder from running away from the surface to be joined
• Braze welding involves melting a non-ferrous filler metal into grooves or as a fillet on the mother metal, without melting the base metal and is commonly applicable for iron-based material parts
• In rubber belts application/mounting, it is advised that it should have an initial tension of 15 to 20 inch/ply
• Normal stress relieving temperature for cast steel is 450 to 550°F
• Nickel is the most effective alloying element for reducing the brittleness of steel at very low temperatures
• A statement that a given body is in static equilibrium means that the body cannot have any type of motion
• Ordinary steel begins to lose strength and elasticity significantly at about 600-700°F
• Clearance to a new boiler installation to the existing or old plant building should follow a minimum clearance of 2130 mm (max) between the top of the boiler proper and the ceiling as stated in PSME Code
• For a high corrosion resistant stainless steel, a minimum chromium content of 8% is required
• Combination chuck is the common type of chuck used for holding a workpiece in a lathe operation
• V-belts operate efficiently at a speed of about 4500 fpm
• Helical gear is used for high-speed operation
• In a pair of gears, pitch plane is the plane perpendicular to the axial plane and tangent to the pitch surface
• Creep is the phenomenon of continuous stretching under load even if the stress is less than the yield point
• Shaping is a machinery operation done with the work accurately fastened has a reciprocating (forward and backward) motion and the tool head is stationary
• Casting does not pertain to joining of metals
• Killed steel is always associated with silicon
• The usual ratio of water to soluble oil used as cutting fluid is 4 to 80 water to 1 oil
• All of these: silicon, manganese, aluminum are good deoxidizer in steel melting
• All of these: columbium, titanium, all of these are Good stabilizer in stainless steel
• All of these: water with soda or borax, light mineral oil, and soluble oil are the common cutting fluids used for cutting metals
• Grease is considered a semi-solid lubricant
• Metals are conductive, since the electrons are loosely bound to the nuclei and therefore mobile
• The yield strength of a regular yellow brass (65 to 75% Cu, 30 to 35% Zn) can be increased/improved by cold working
• 0.20 % C would be used in as cast condition steel casting with carbon content less than
• Liners are normally made of cast iron
• Endurance strength is nearly proportional to the ultimate strength but not with design stress, shear stress and all the above
• A crucible furnace melts non-ferrous metals

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• The lead of a helical gear or worm thread is the distance along its axis in one revolution if it were free to move axially
• Length of engagement is the length of contact between two mating parts in a screw and nut threads measured axially
• Uniform motion is when the velocity of a mass is small all the time during which motion takes place
• Poisson's ratio relates the lateral strain to longitudinal strain of a material
• An eccentrically loaded bearing is also called an offset bearing
• In regular lay wire rope, the wires and strands are twisted in opposite directions

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• In involute teeth, the pressure angle is often defined as the angle between the line of action and the line of tangent to the pitch circle, also termed angle of obliquity.
• For a mechanical plant with a capacity of 300 kW or over but not more than 2000 kW, the required personnel must be at least a CPM (Certified Plant Mechanic), ME (Mechanical Engineer), and PME (Professional Mechanical Engineer)
• 1/8 divided by 8 equals 1
• Rubber is a product of combustion that has a property of resilience
• Addendum is the height of a tooth above the pitch circle, or the radial distance between the pitch circle and the top land of the tooth
• The function of a clutch in a machine is to disconnect or connect the drive at will

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• A designer should add a hunting tooth to evenly distribute the wear on meshing teeth like a 53 teeth gears with 30 teeth pinion, find rotation of pinion to mesh with same pair of teeth again is 53.
• The lead angle is the angle made by the helix of the thread (in a straight thread) at the pitch diameter with a plane perpendicular to the axis
• In journal bearing design, the clearance ratio/clearance should be 0.0010
• The moment of inertia of a rectangle whose base is "b" and height "h" about its base is bh3/3
• Cold rolled shafting is not available in diameter larger than 5 inches
• Cast iron flywheels are designed with a factor of safety of 10 to 13

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• A couple is a pair of equal and opposite (not collinear) forces that tend to cause a rotation of a body.
• The English module is the ratio of the pitch diameter in inches to the number of teeth.
• Ft-lb is a unit of energy.
• When high strength and durability are a requirement for choosing gear materials is preferable to use steel material
• Non concurrent forces are forces when action are parallel
• Linear momentum is the product of the mass and the velocity of the center of gravity of the body is called

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• Pitch is defined as the distance between similar, equally spaced tooth surfaces in a given direction and along a given line.
• Could be defined as simply push or pull is termed as force.
• A couple involves opposite directional forces that are equal in magnitude and parallel.
• Scalar quantities such as time, volume, and density are fully described when their magnitude is specified.
• A designed 200 kW plant must have at least a PME (Professional Mechanical Engineer)
• Component forces are the separate forces that can be combined

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• A licensed ME (Mechanical Engineer) is allowed to operate, tend or maintain a maximum plant capacity of 2000 kw
• When the motion is diminished / decreasing instead of increasing is called retarded motion
• Graphite lubricants are known lubricants that being utilizes in whatever category of load and speed are oil, air, grease and dry lubricants
• A flexible disk coupling is a coupling that allows axial flexibility movement in the operation and it is made of alternate bolting of steel, leather, fabric, and/or plastic material into two flanges
• Four bar linkage has two cranks, a stationary piece called the line of centers, and the connecting rod is a
• Rack gears is used to change rotary motion to reciprocating motion

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• Approach ratio is the effective face width of a helical gear divided by gear axial pitch.
• Pitch diameter less the diameter of the roller chain is equal to bottom diameter
• Worm gears are generally applied on speed reducers due to large speed ratios.
• If the shaft size is specified as diameter 2.00" max and 1.99" min in diameter then the 0.010" could be defined as tolerance
• A material subjected to a load which then the strain disappeared when the load was removed, then it is termed elastic
• Helical angle in the range of less than 15 degrees is recommended for wide-face helical gears.

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• Allowance is the difference between maximum material limits of mating parts. Or it is a minimum clearance or maximum interference between parts
• Fillet curves is the concave portion of the tooth profile where it joins the bottom of the tooth
• Strains are the changes in shape or geometry of the body due to action of a force
• For an evenly and uniform wear on each meshing gear tooth, the ideal design practice is to consider a hunting tooth addition
• Module is define ad the reciprocal of a diameter pitch of the ratio of the pitch diameter to the no. of teeth.
• Ability to resist deformation under stress is termed stiffness

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• Flat leather belting is not recommended for used in a speed that exceeds 6000 fpm
• Angle included between the sides of the thread measured in an axial plane in a screw threadis is termed as angle thread
• An elastic body whose primary functions is to deflect under load is called Spring
• Poisson's ratio is the ratio of lateral deformation to the longitudinal deformation
• Manganese steel standard designation, SAE 13XX
• Tool and die steel is not a structural steel

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• Moment of inertia on a cross-section relate to it's section modulus and that it's equal to a measure of distance
• The SAE 2340 shafting contains 3.25 to 3.75% nickel
• To operate or maintain of any mechanical works, projects or plants of over 2,100 kw, must be a duly licensed PME
• Chromium steel standard designation, SAE 5XXX
• Chromium is an alloy that improves strength of steel at high temperature application
• When air entrainment agent is put into a concrete mix, the strength will decrease

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• Alloys with high nickel content retains toughness to quite low temperatures up to -320 °F
• The differential of the shear equation is the load on the beam
• It is recommended not to have direct drive between driven and drive sprockets if the ratio of their teeth exceeds 10 times
• The length of the hub should not be made lesser than the face width of the gear. Hub lengths usually vary from 1.25 D to 2D, where D is the shaft diameter. The reasonable diameter of steel hub should be given when equal: 1.8D
• The sum of their addendum and dedendum is in the whole depth
• For high speed application that the minimum number of teeth in small sprockets, which should be 18 to 24

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• Stresses independent of loads is called residual stresses
• Nickel is a material having high electrical resistance and shouldn't be used as conductor of electrical current
• The best material for brake drums is the cast iron
• The alloy materials used in the production of metal working tools like high carbon steel material
• Torsional deflection is a significant consideration in the design of shaft and the limit should be in the range of 0.08 to 1 degree/foot of length The value of threads per inch if the pitch of a screw is 2/9 is 4.5

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• Shafts readily available in the market are made in many ways and wide variety of material composition and likely be cold drawn carbon steel in size smaller than 3.75 inches diameter are preferred
• Plain carbon steel standard designation, SAE 10XX
• The rigidity of polymer can be increased by crystallization
• Cast iron has lower strength and more brittleness, also has lower ductility than cast steel
• For line shaft carrying pulley, a general practice is to use the following allowable stresses when at 6000 psi
• Drilling machine cannot do broaching

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• Material changes in foundry melting operation occur in limestone, foundry coke and silica sand
• Carriage stop- is a work supporting device which is bolted to the saddle of the lathe machine and travels with the cutting tool and also preventing the springing away of the workpiece from cutting tools
• Almost always the soldering materials are a combination of lead and tin alloys
• The most popular of all soldering materials in use has composition of 50/50% tin and lead
• The relative strength of a butt weld could be safely assumed as 90% efficiency
• Silica sand, bentonite, and flour/paste water are materials used in the foundry molding operation

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• The following are parts of a micrometer caliper except for the head screw
• The residual stress in welding of avoiding brittleness is normally stress-relieved in tempering
• The steel with certain % of carbon maximum used which can readily be welded by all process and the resulting strength of the portion welded is as strong as the base material is: 0.30% C
• Aluminum is commonly used by steel melter as deoxidizer because of its easy availability and cheap
• Involute refers to the curved formed by the path of a point on a straight line as it rolls along a convex base curve, which the base curve is usually a circle and generally used as the profile of gear tooth
• The several forces combined is called components

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• The ideal herringbone gear helix is in the range of 30 to 45
• Pitch is defined as the distance from a point on a screw thread to a corresponding point on the next thread measure along the axis
• The distance of recommended the center to center distance between sprockets should not be less than 1% times the bigger sprocket
• Measuring device with ability to check flatness of plane surfaces with 10ths of thousands centimeter using planimeter
• The tools usually used in wood pattern making in a foundry shop are saws and chisels
• The value of linear deflection to inch/foot of length in practice design of steel line shafting is: .010

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• Big chain sprocket wheels are designed as spokes/arms are with major axis: 2 times the minor axis
• SAE 40xx defines an standard tool designation and is used with Molybdenum
• In order used and application of tolerances with specific combinations is as follows: fit
• The value of degree in radian measure which equals 57.296 Degrees
• Kinematics viscosity shows the density and expressed also as the same unit of absolute viscosity in same unit standards measurements
• The use and color sign use in communication are in white in colors
• Crest clearance defines the perpendicular measured from the axis between the crest of the roots and assembly mating threads of screws
• It is called full-bearing because it is defined as a bearing and surface journal that completely surrounds the journal
• Backlash defines as the width of a tooth spaced exceeding for the engagement tooth of each thickness in a pitch of the circle

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• Additional elements to enhance resistance to atmospheric corrosion in steel is to adds Copper properties
• Two and equality and in some cases it’s already in equilibrium and the stability still remains
• Iron content with allots of 9 to 16 in material is commonly used as Stainless
• When designing a the limit that commonly recommended with cast flywheels and its limits is 3050ft/ min

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• As defined as the nearest in center to center between the rivet is defined as pitch As according of purpose in lubrication, all purposes and definition it should
• Lighten and decrease load capacity Joint portion process and avoiding of peening is to avoid structural fusions due to weld process and is defined as Annealing
• In a forces of two a a combination of component is often described at resultant When designing equipment it defined to to be around 3 to 5 of weight compared to the device

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• American Iron and Steel Institute is not an associated with standard material specification, EXCEPT:
• For maximum quietness in sprocket drive operation choose 27 or more teeth
• The common biggest diameter of cold rolled steel is 5 inches in diameter
• The appropriate and assign for communications Is white color

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• The definition of stud bolt is defined as: Type of bolt commonly used in the construction that is in both ends
• When measuring for helix angles the values commonly remain at: 15 to 25 The constant relationship in elasticity relating to stress an ratio can commonly be defined as: bulk modulus
• Equipment foundations is around 3x to 5x of the total machinery and welding edge is related to a parallel alignment of the edge and called edge joint
• The class of equipment with decreased electrical conductivity with increasing temperature of the materials are metals

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• The cast iron flywheels are commonly designed with a safety factor of: 10 to 13
• Stress relieving is also defined as Normalizing for specific used and purpose of the steel material to reduce from it with a metal of specific used
• When defining a uniform in helix its a screw threads
• To design in martensitic design standards containing an standards in composition can be no more or equal to 2.5
• For the following relationship with stress design is measured with stress and by following it with the equation and factor of safety

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• 3.2 Is mostly defined and used in most wear parts of machinery or in contact is classified as abrasive
• Resultant occurs in forces with two forces action
• 32 Peculiar strength is known to hold the most metal and is very resistive to to being most broken down, what is: compressive strength A good non viscoelastic is to add metal materials
• For the materials commonly used in the bolts is: AlSI2330 What does material of removing a machines by: machines with high speed tool steels;

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Design with a chain that the tight most and recommended angle is: 45-55 To increase what is made from carbon can be: 0.50 plus Good teeth are also known for their ability to be: bottom land

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• Web or drill bits can be: nearing the shank
• Machining surfaces show as what signal:f
• The must maintain features that are commonly require for shop operations:safety notices
• Deflections are commonly set for inversion based the moment of inertia
• Most teachers that are required must be: PM
• Amount to value gear pinion addendum is: Clearence

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• Circular groove axial are keyseat
• Material heaviness by water equal is specific gravity
• Commonly produce screws and bolts from series is UNC
• Eqiup foundation vibration are 10-2
• Reciprocular motion is Oscilation
• Stell with Nichol and chromium is SAE 49

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• Moment of inertia is also called: Radius Gyration
• Hardening and treating and heat up suddenly improves material
• Surface and crest of screws is flank
• Good general de-oxidation will occur is by Silicon
• Process of treatment produces a residual compressive stress and is: shallow quenching.

Questions cover meshing gears, material deformation under load, machining processes, metalworking, and steelmaking. Includes deoxidizers and cutting fluids. Focus on engineering principles.