MDSP-Terms-2 PDF - Mechanical Engineering Terms

This minimum distance is measured between the non-driving side of a tooth and the adjacent side of the mating tooth. It is the amount by which the width of a tooth space exceeds the thickness of the engaging tooth measured on the pitch circle. What is this distance? Backlash  Wh...

This minimum distance is measured between the non-driving side of a tooth and the adjacent side of the mating tooth. It is the amount by which the width of a tooth space exceeds the thickness of the engaging tooth measured on the pitch circle. What is this distance? Backlash  What is the algebraic difference between the maximum limit and the corresponding basic size? Upper Deviation  This is either the upper or the lower deviation, depending on which is closer to the basic size. How do you call this deviation? Fundamental Deviation How do you call the strain energy per unit volume required to stress a material from an unloaded state to the point of yielding? Modulus of Resilience How do you call a structural member designed to support loads perpendicular to its longitudinal axis? Beam It is a load applied transversely to longitudinal axis of member. Bending load What is a load distributed over an entire area? Distributed load It is a design approach where no catastrophic loss can occur as a result of a component failure. Fail-safe design approach It is a computational method used for solving complex shapes, such as those found in machinery; replaces the complex shape with a set of simple elements interconnected at a finite set of a specific purpose. Finite element analysis  When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some metal parts under certain conditions crack as a result. How do you call this phenomenon?. Thermal-shock failure How do you call the diameter of the imaginary cylinder that bounds the crest of an external thread and the roots of an internal thread? Major diameter It is a measure of the change in length of a material subjected to a change in temperature. Coefficient of thermal expansion How do you call the circle on a gear that corresponds to the contact surface of the friction wheel? Pitch Circle  This material is the most popular alloy spring steel for conditions involving higher stresses than can be used with the high- carbon steels and for use where fatigue resistance and long endurance are needed; this is also good for shock and impact loads. Chrome Vanadium  A bearing that primarily guides the motion of a machine member without specific regard to the direction of load application. Guide bearing  Which of the following are the compositions of stainless steel 302? 18 % chromium and 8 % nickel These springs are made from one or more flat strips of brass, bronze, steel or other materials loaded as cantilevers or simple Leaf Springs  This refers to the space between adjacent coils when the spring is compressed to its operating length. Coil clearance  In a lathe machine, it is the diameter of the largest workpiece it can rotate in a chuck or between centers without hitting the bed. Swing This is a lubrication condition where non-conformal surfaces are completely separated by lubricant film and no asperities are in contact. Elastohydrodynamic lubrication How do you call the flattened end of a shank, and intended to fit into a driving slot in the socket? Tang  How do you call the process of producing the residual compressive stress of machine parts, which is performed by directing the a high velocity stream of hardened balls or pellets at the surface to be treated. Shot blasting  It is a process that produces residual compressive stress on the machine part, which uses a series of hammer blows on the surface. Peening It is a surface-hardening process for alloy steels in which the material is o heated to 950 F in a nitrogen atmosphere, typically ammonia gas, followed by slow cooling. Nitriding  Which of the following gases is typically used in nitriding process of surface hardening? Ammonia gas  Which of the following is the benefit in using nitriding as a surface-hardening process for alloy steels? Improvement of endurance strength, 50 % or more  In estimating the actual endurance strength of steel parts, one of the factors to be considered is the material factor, which of the following is the recommended material factor for cast steel? Material factor for cast steel = 0.70  Which of the following column formulas is applicable to cast iron columns? Straight line formula Which of the following ferrous metals has the lowest carbon content?  Wrought Iron Wrought iron usually contains less than 0.04% C; steel usually has less than 2.5% C; cast iron has more than 1.7% C; SAE 4140 has approximately 0.4% C. If stiffness is the main criterion in selecting a material, which of the following is the most economical choice? a) SAE 3130 b) SAE 1020 c) SAE 6150 d) AISI 301, ¼ hard stainless steel SAE 1020- plain carbon steel. All of the above materials are steel with practically equal modulus of elasticity. The three other materials are alloy steels that are relatively more expensive Which of the following materials can easily be machined? a) AISI C1020 b) AISI C1112 c) AISI C1030 d) AISI C1010  AISI C1112. This is a free-cutting steel with a higher sulfur content for ease in machining Wood is an ______ material; that is, its mechanical properties are unique and independent in three mutually perpendicular directions—longitudinal, radial, and tangential. Orthotropic material The principal raw materials used in steelmaking are iron ore, coal, and ____ Limestone  The primary application of high- speed steels is to tools used for the working of metals ____ At high cutting speeds In gearing, this is the ratio of the arc of action to the circular pitch. Contact ratio  Flywheel arms are usually of elliptical cross-section, the strength of the arms should equal ___ the strength of the shaft in torsion. Three-fourth This alloy (nickel, iron, chromium, cobalt is a non- magnetic, corrosion resistant material suitable for sub-zero temperatures and temperatures up to about 750 degrees F., provided that torsional stresses are kept below 75,000 pounds per square inch. It is precipitation-hardened to produce hardnesses of 48 to 50 Rockwell C and is used in watch and instrument springs. Dynavar; source: Machinery’s handbook  To ensure an adequate factor of safety in the design of a shaft with standard keyway, the key width should be about: One-fourth of the shaft diameter What is the property of matter that causes it to resist any change in its motion or state of rest? Inertia This is defined as the cutting time to reach a predetermined wear, called the tool wear criterion. Tool life Which of the following G-codes refers to rapid traverse in CNC machining? G00  An acronym in CNC machining which means access of the machine operator to insert machining instructions directly into the NC machine control system via push buttons, pressure pads, knobs, or other arrangements.? MDI = manual data input  The variable polarity plasma arc (VPPA) process was developed for welding metals that form an oxide skin, such as ___________. Aluminum If the steel is strongly deoxidized by the addition of deoxidizing elements, no gas is evolved, and the steel is technically called _______because it lies quietly in the molds. Killed steel Stainless steels generally contain at least __ per cent chromium, with or without other elements. 10%  What grades of stainless steels are nonmagnetic in the annealed condition, although some may become slightly magnetic after cold working? Austenitic grades These steels (SAE Steels 1006, 1008, 1010, 1015) are the lowest carbon steels of the plain carbon type, and are selected where ________ is the primary requisite of the user. Cold formability At certain speeds called the critical speeds, a rotating shaft will become dynamically unstable and the resulting vibrations and deflections can result in damage not only to the shaft but to the machine of which it is a part. At what percentage of the critical speed should a shaft be safely operated? Plus or minus 20 %  In die casting accurate parts made of steel, what shrinkage allowance in inches per inch is recommended? 0.022. (Source: Machinery’s Handbook)  This are gears used to connect shafts that are non-intersecting and non-parallel. They are a cross between spiral bevel gears and worm gears. Hypoid gears  This is a type of seal used where some form of relative motion occurs between rigid parts of an assembly. Dynamic seal It is a lubrication for roller chains wherein the lubricant is supplied by a circulating pump capable of supplying the chain drive with a continuous flow of oil inside the chain loop evenly across the chain width and directly at the slack strand. Oil stream lubrication  In manufacturing, this is the operation of cutting out flat area to some desired shape and is usually the first step in a series of operation. Blanking An M-code which generally refers to start spindle rotation in a clockwise direction. M03 A final operation to improve the polish of a metal and to bring out the maximum luster Buffing  A material of construction (only developed commercially in the late 1940’s concurrently with zirconium) offers the unique combination of wide ranging corrosion resistance, low density, and high strength. Titanium  This process reduces internal stresses, caused by machining, cold working, or welding, by heating the steel to a temperature below the critical range and holding it there long enough to equalize the temperature throughout the piece. Stress Relieving  A free-cutting steel has a higher ______ content than comparable carbon steels. Sulfur This property designates the steels resistance to the softening effect of elevated temperature. Hot hardness In braking, the term backstop refers to a brake that is: Self locking in one direction How do you call a fixed crane consisting of a supported vertical member from which extends a horizontal swinging arm carrying a trolley hoist or other hoisting mechanism? Jib crane This iron is also known as a ductile cast iron Nodular cast iron It is the ability to deform plastically to compensate for irregularities in bearing assembly. Conformability  Newton’s law of motion that describes that if a force acts to change the state of motion of the body, the body offers a resistance equal and directly opposite to the force. Third law These are steels most widely used of engineering materials. No other material offers comparable versatility for product design. Wrought steels Which of the following steels does not readily respond to heat treatment? a) SAE 1045 b) AISI 6150 c) SAE 1020 d) SAE 1095  SAE 1020 o Low carbon steels (0.3% C and lower) do not readily respond to heat treatment. Rivet holes are made usually ____ inch larger in diameter than the nominal diameter of the rivet. 1/16  Which of the following equations/formulas does not belong to the group? a) Lame’s equation b) Euler’s formula c) J. B. Johnson’s equation d) Secant formula Lame’s equation is an equation for a thick-walled pressure cylinder. The other 3 are for columns. In CNC programming, which of the following G code commands is for dwell or rest? G04  In CNC programming, which of the following M code commands is for a tool change? M06  The true stress-strain curve in a stress-stress diagram appears to be: Higher than the engineering stress-strain curve This is a hardening treatment for steels having low carbon content. Case hardening What is a manufacturing process used for the production of aluminum? Extrusion This refers to a loss of material from the interface of two metal surfaces that are in intimate contact Fretting corrosion  This is a type of fit that requires heating the hub to expand its inside diameter. Shrink fit AFBMA is an acronym for an association involved in what machine elements?  Ball and roller bearings AFBMA means Anti-Friction Bearing Manufacturers’ Association and is concerned with rolling element bearings such as ball, roller, and needle bearings. What is the general description for mild steel? Low carbon steel Von Mises theory is the other term used for Octahedral shear-stress theory In the design of key, the typical hub lengths are in accordance with the following relation where D is shaft diameter. 1.25D to 2.4D  A coupling that allows axial flexibility/movement in the operation. Made of alternate bolting of steel, leather, fabric and/or plastic material into two flanges Flexible Oldham coupling  It is a machine member that supports another part that rotates, slides, or oscillates in or on it. Bearing  It is a bearing that permits constrained relative motion of rigid parts; lubricant is generally inserted or supplied between the mating surfaces to reduce friction and wear, and to carry away the heat generated. Sliding Contact Bearing  These are surfaces that do not conform to each other very well as in the rolling-element bearings. Non-conformal surfaces The study of lubrication, friction, and wear of moving or stationary parts is known as: Tribology A bearing where surfaces are non- conformed and motion is primarily rolling; it composed of rolling elements interposed between an outer ring and inner ring: Rolling-element bearing In a straight bevel gear, how do you call the angle between an element on the pitch cone and an element on the face cone? Addendum angle It is a Grashof four-bar mechanism in which the shortest link is the frame or fixed link and the other two cranks completely rotate with their axes. How do you call this Grashof four-bar mechanism?? Drag-link mechanism “For a planar four-bar linkage, the sum of the shortest and longest lengths cannot be greater than the sum of the remaining two link lengths if there is to be a continuous relative rotation between two members.” Grashof’s Law It is a Grashof four-bar mechanism in which the shortest link is the frame or fixed link and the other two cranks completely rotate with their axes. How do you call this Grashof four-bar mechanism?? Drag-link mechanism This is a shaper operation, which is shaping the given stock and having the excess material remain with a tolerable allowance for finishing Roughing  This is the trade name for a patented alloy made up chiefly of cobalt, chromium, and tungsten in varying proportions. Stellite  This is a combination of mechanisms and other components that transforms, transmits, or uses energy, load, or motion for a specific purpose. Machine  How do you call a load that is applied transversely to longitudinal axis of member? Bending Load  What is the other term for the Maximum-Shear-Stress Theory, as a failure prediction theory? Tresca yield criterion This is a theory in cyclic and impact loading, which states that damage at any stress level, is proportional to number of cycles. What is this theory commonly called? Miner’s Rule How do you call a ball bearing with race containing pronounced groove for rolling elements? Conrad bearing  This is a set of specifications for the analysis, design, manufacture, and construction of something; the purpose of which is to achieve a specified degree of safety, efficiency, and performance or quality. Code What is the algebraic difference between a size and the corresponding basic size? Deviation This is used either for very accurate angular measurements or for locating work at a given angle; is used together with precision gage blocks. What is this? Sine bar  What is a set of specification for parts, materials, or processes intended to achieve uniformity, efficiency, and a specified quality? Standard