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Correct choice is (b) False

To explain I WOULD say: In the tube drawing process, the deformation is usually uniform throughout the tube. The process is a cold WORKING process which causes residual STRESSES in the tube material. In general, the longitudinal residual stresses are TENSILE on the exterior surface and compressive on the INTERIOR surface of the tube.

Correct option is (b) False

For explanation: In ROTARY swaging, the MAIN benefit of the INCREMENTAL forming process is the minimum friction, because the time of contact between the dies and material is very small. And the relative movement is very small during the contact, so wearing of dies does not take PLACE easily during the process.

The correct option is (b) False

To EXPLAIN I would say: In rotary swaging process, the radial motions of the dies are very important for most of the applications. In general, a die set mainly consists of FOUR die segments which basically depends on the type of APPLICATION or USE, and also depends on the size of the machine tool. In special cases of swaging, the number of die sets can be used up to eight dies.

Correct choice is (a) True

Explanation: Bar or rod drawing process can be performed in single draft. A draft is a difference between the initial and FINAL diameter of the METALLIC bar used. WHEREAS, for wire drawing process a small diameter metal bar is used. And wire drawing is basically DONE in multiple steps which USE nearly around 4 to 12 dies.

Correct answer is (b) False

To EXPLAIN: It is very important to select appropriate rolling speed in THREAD rolling process to produce products of better thread quality and for long life of the rolls. The rolling speed MAINLY depends on the tensile strength, the speed capabilities of the machine and the thread form to be rolled. In general, the rolling speed KEPT is very high. But if the speed is too low, then it may cause damage to the rolls.

Right ANSWER is (a) True

The explanation is: In stretch metal forming process, the forming LIMIT curve (FLC) provides quantification about the formability of sheet metal, which basically gives the details about the quality of material. The forming limit curve (FLC) is generally defined as a locus of all the limit strains in different STRAIN paths like deep drawing and biaxial STRETCHING, of the sheet metal.

Right option is (a) True

Explanation: Rotary swaging is a forming process which is MAINLY used for MAKING tubes with high PRECISION. This process can also be used making rods or bars, and it basically belongs to the group of net-SHAPE forming processes, of which ONE of the features is that the finished shape of the material is produced without or with only a small quantity of further final processing by finishing.

Correct choice is (a) True

The best I can explain: Rotary swaging is basically an incremental FORMING process which is also called as oscillating forming, because it takes place in many small processing steps. One of the benefits of the incremental forming process COMPARED to the CONTINUOUS processes is the homogenous forming of the material. HIGH forming ratios can also be achieved by a rotary swaging process in a single processing step.

Correct choice is (b) False

Easiest explanation: In the swaging process, the forming dies of the swaging machine are GENERALLY arranged concentrically around the material rod. The swaging dies OPERATE with high frequency radial motions and with small strokes. The stroke FREQUENCIES commonly range from 1500 to 10000 per minute which basically depends upon the size of machine or EQUIPMENT.

Right choice is (a) True

To elaborate: In the swaging PROCESS, hammering action is produced which provides better surface finish, tensile strength and better grain structure to the material. In this process, the work-piece should be completely clean and dry, and without any KIND of LUBRICANT. This METHOD is very simple and can be PERFORMED by any unskilled operator.

Correct OPTION is (a) True

Explanation: In swaging process, the formation of longitudinal BURRS at the gaps between the dies is generally PREVENTED by providing relative ROTATIONAL motion between the dies and the materials. The swaging dies rotate near the material or alternatively, the material rotates between the die segments.

Correct answer is (a) True

For explanation: In the ROD or bar drawing process, the entrance of the die ASSEMBLY includes a bell assembly which facilitates the entry of lubricant along with the metallic bar during the process. The bearing area causes FRICTIONAL drag on the metallic bar and generally HELPS in the movement of the metallic bar inside the die mechanism.

The CORRECT answer is (c) Tensile

The best explanation: Rod or tube drawing is a DEFORMATION PROCESS in which the metallic material in the form of cylindrical bar is pulled by the help of a converging die. In general, the tensile STRESS is applied during the process. The strain hardening occurs which makes the material very hard and strong by reducing its ductility.

Right answer is (a) True

Explanation: In stretch forming, a metal sheet is stretched by the help of stretcher machines. For proper and complete STRETCHING of sheet, the MATERIAL is deformed plastically which is ALSO CALLED as permanent deformation. The metal sheet is stressed above its yield strength for successfully achieving the PLASTIC deformation of the metal sheet.

Correct option is (d) Stretch forming

To explain: Stretch forming is a sheet metal forming process in which the sheet metal is clamped at the edges and stretched by USING the dies or form blocks. And no any lubrication is required significantly during the process. This method is BEST suited for MAKING the PRODUCTS LIKE aircraft wings, window frames, automobile door panels etc.

The correct answer is (b) False

Explanation: The tube DRAWING process can be accomplished by with or without mandrel. Mandrel basically consists of a hard ROD or wire that extends over the entire length of the tube and is drawn through the die along with the drawing tube. The frictional PROBLEMS can be greatly reduced by PROVIDING a LONG mandrel in the tube drawing process.

The correct answer is (a) True

Explanation: After tube drawing PROCESS, the MANDREL should be removed from the tube which can be DONE by the reeling process. The REMOVING process INCREASES the tube diameter and also disturbs the dimensional tolerances. So, great care should be taken while extracting out the mandrel from the inside of tube.

Correct choice is (a) True

Best explanation: Rubber forming is a TYPE of forming process in which a polyurethane or rubber PAD is commonly used as the die material instead of a rigid material. These materials are highly resistance to the ABRASION and have a better fatigue life. And pressures of the order of 100 bar are typical of this process. This process is ALSO called as Guerin process.

Right option is (B) False

Best explanation: In the tube drawing PROCESS, when a hollow tube is DRAWN through a die, usually a mandrel or plug is used, which BASICALLY supports the internal diameter of the tube. The function of the mandrel mainly is to affect the wall thickness reduction and also used for controlling the shape and size of the hole in the tube.

The CORRECT choice is (b) False

To elaborate: Swaging is a metal forming process of reducing or shaping the cross-section of metallic rods by means of repeated impacts or BLOWS. This process basically CONSISTS of dies which are GIVEN the required external shape. These dies intermittently IMPACT the material to produce the deformation.

The correct choice is (b) False

Easiest explanation: In ROD drawing process, a bar or rod is drawn in order to reduce its diameter. The drawing OPERATION results in the reduction in cross-sectional area of the material by increasing its length. This process is BASICALLY a KIND of cold working process which takes PLACE below the re-crystallization temperature of the material.

Correct answer is (b) False

For EXPLANATION: Stretch forming is a TYPE of sheet metal forming process in which the metallic sheet is intentionally stretched and BENT simultaneously to produce different SHAPES of the stretched sheet metal. The metal sheet is generally held by JAWS at the ends. And then the sheet is stretched by the help of punch.

The correct answer is (a) True

For explanation: Tube drawing a kind of metal forming process which is very similar to bar drawing process, except the beginning of input material is a tube. This process is used to REDUCE the diameter, IMPROVE the SURFACE finish and improve the dimensional accuracy of the metal tube. In this process, a mandrel may or may not be used, which mainly DEPENDS on the PURPOSE.

The CORRECT CHOICE is (a) True

Explanation: Rod drawing is a cold working process in which strain hardening occurs. Over drawing or reduction in cross-sectional area of bar beyond a certain limit can cause poor surface FINISH of the product. During this stage, the need of tensile stress increases SUBSTANTIALLY and the material BECOMES very hard and strong due to the reduction in its ductility.

Right option is (a) True

The BEST explanation: Intermediate annealing is basically a kind of heat TREATMENT process in which the material is heated and gradually cooled in order to obtain strength and ductility in the material. During the process of rod drawing, WORK hardening occurs which causes MATERIALS to be hard and less ductile, so for maintaining its mechanical properties, the intermediate annealing is performed.

The correct choice is (B) False

Best explanation: In rod DRAWING PROCESS, the metallic rod is FIXED into the dies by using a die holder and then a drawing head is used in which the metallic rod is fixed through a jaw mechanism. And then the bar is stretched and slides between the surfaces of the die, which causes friction and wearing. So to avoid such wearing, the rod is first lubricated before going into the process. In general, soap solution or oil is used for the LUBRICATION in rod drawing process.

Right answer is (a) True

Explanation: TUBE DRAWING process is very ECONOMICAL and best suitable for producing tubes with thinner walls of high dimensional accuracy and close tolerances. This process is basically a cold working process which takes PLACE at the room temperature or slightly above it. This process also provides better surface finish and enhances certain mechanical properties in the tube material.

Correct answer is (a) True

To explain I would say: In rotary swaging, the processing of the material is done by minimum relative MOTION and therefore minimum friction is present between the DIES and materials. So the LUBRICATION is not required significantly, but it is enough to use OIL in a closed cycle which basically acts as a coolant or can be used for cleaning PURPOSE.

The correct option is (b) False

For explanation: In thread rolling process, it has inherent ABILITY to maintain the ACCURACY in the production of threaded bolts. It can maintain high level of accuracy; this is basically due to well and precise settlement of MACHINE parts during high speed production. Thread rolling also provides BETTER FINISHING to the formed materials.

Right choice is (B) False

The best I can EXPLAIN: In thread rolling, threaded rollers are used which forces their thread into the rolling MATERIAL. And the threads are formed on the material, which then comes out from the machine. The thread is formed on the bolt, but this process does not EXCEED the length of rolling bolt during the OPERATION.

Right option is (b) False

Explanation: Spring-back is basically defined as a phenomenon in which the MATERIAL tries to REGAIN its original shape during elastic loading condition. But in stretch FORMING process, the stretching and bending operations take place simultaneously which causes permanent deformation of the sheet metal. So, this combined effect results in negligible spring-back in the metal part and HENCE causes no problem in the operating MACHINES.

Right option is (a) True

The explanation: TUBE drawing process can be performed with or without mandrel, depending on the features required in the drawn tube. The mandrel is GENERALLY excluded if it is not necessary to make a REDUCTION in the wall thickness, or if the DIMENSIONS and surface finish are not important. The process of drawing a tube without the use of any mandrel is basically known as tube sinking.

Right answer is (b) False

For explanation I would say: In the swaging process, tubes can be swaged with or without the application of mandrels. In the case of swaging without mandrels, the surface finish obtained will not be proper and ACCURATE when a blow is APPLIED onto the material during the operation. When the length and THICKNESS of the material increases simultaneously, then the need of MANDREL becomes essential.

The correct answer is (b) False

Easiest explanation: Thread rolling process is very fast and it can PRODUCE threads on the BOLT extremely fast. So this process can form HUNDREDS of bolts in few minutes. And this process is highly economical for producing threads on the bolts. However, the process is costly, but best suited for large SCALE production of bolts.

The correct CHOICE is (b) False

The best explanation: In tube drawing process, the drawing equipment can be of several designs. In general, these designs are mainly classified into two types, which are DRAW bench and bull block. Draw bench type uses a single die and the pulling force is applied by a chain mechanism or by hydraulic system. It is mainly used for single LENGTH drawing of tube or ROD.

Right choice is (b) False

To explain I WOULD say: In GENERAL, the output of extrusion process can be the input of TUBE drawing process. In tube drawing process, the diameter and thickness of the tubes that have been formed by extrusion or other processes can be further DECREASED by tube drawing process. This process is almost similar to wire or rod drawing process except that it requires a mandrel to INITIATE the forming operation.

Right answer is (b) False

Best EXPLANATION: In rod drawing process, a draw bench is USED instead of a form roll for drawing of rods or bars because rods cannot be coiled on any roll. The rod or bar is USUALLY pointed by swaging operation and then fed into the drawing DIES. And the tip of the rod is clamped into the JAWS and then drawing process is carried out continuously.

Correct option is (a) True

Explanation: In thread ROLLING, a complete thread is generally formed where the grain of the material FOLLOWS the form or shape of the thread, which considerably INCREASES the STRENGTH of the thread. In this method, all thread forms can be formed in a single pass, which basically includes buttress, knuckle and trapezoidal THREADS.

Right option is (a) True

The explanation: The stretch forming process is GENERALLY performed by using a HYDRAULIC OPERATED ram. In this process, first a SINGLE form block is used along with the gripping jaws, and then the metal is gripped and stretched by applying high tensile forces until it deforms plastically. And then the SHEET metal is bent and rolled around a form block.

The CORRECT answer is (a) True

Explanation: In thread rolling process, the process is CARRIED out at much FASTER rate than the thread cutting process. This basically reduces the machine CYCLE time. In this process, the blank is produced at the pitch diameter of the thread, but in cut threads the blank is prepared at the major diameter. So, more material is required during the process.

Correct choice is (B) False

To explain: Wet drawing basically involves dipping of METALLIC bar inside a lubricant bath before the next processing stage. In this process, the rod is LUBRICATED by using lubricants like soap SOLUTION or oil. Lubrication can also be done by applying a coating of SULFATE onto the material in order to retain the lubricant on the surface of metallic bar.

The correct answer is (b) False

Best explanation: In stretch forming, the sheet METAL is fixed with stretch gripper with the support of a tool, and then operation takes place in a hydraulic stretching unit. The process consumes too MUCH TIME as the stretching process takes time to strain HARDENS the material. So, this process includes LOW volume rate of production, but the process is very versatile and have economic production.

The correct option is (b) False

The best I can explain: Tangential stretch forming is very different from SIMPLE stretch forming. However, the purpose is same. In tangential stretch forming, the metal sheet is gripped from two opposite ends. The main difference to the simple stretch forming is that the form BLOCK and gripping JAWS both are movable in this PROCESS.

Right choice is (a) True

The best explanation: In STRETCH forming process, stretching of a metal sheet is basically done by HOLDING its edges and bending it on a cylindrical block, simultaneously is known as stretch forming. This process basically INVOLVES tensile and bending FORCES during the operation. In this process, the materials with high ductility are mostly stretched by rigid dies.

The correct OPTION is (b) False

Explanation: In general, the selected blank should be STRAIGHT and possess better SURFACE finish for the process of THREAD rolling. In this process, a chamfer is used which GENERALLY present at the start of the blank and also at the end when the thread is to end at an undercut. The selected chamfer diameter should be slightly less than the core diameter of the thread for taking place of efficient operation.

The correct choice is (a) True

Best EXPLANATION: In thread rolling, it is very important that the diameter of the selected blank should be correct. If the blank is undersize then the effective diameter of the thread may formed, but the major diameter cannot be formed. And if the blank is OVERSIZE, then the EXCESS of material WOULD be forced into the rolls, which may further cause damage to the rolls.