Specify rivets The common types of rivets and state their uses Rivets are cylindercal rods having heads of various shapes. Theys are used for assembling the parts of a workpiece together. Specification of a rivet The rivet is specified by the shape of the head diameter, and the length. Shape of head The shape of the rivet head is to be selected according to the intended use of the workpiece to be riveted. Diameter The diameter is to be selected depending on the required strength Length Length is to be selected depending upon the thickness of the components to be riveted Types and uses Snap head It is the most commonly used form, and it gives a very strong joint. Pan head It is used where strength is the only consideration such as heavy structural work . Conical head It is generally used in light assembly where riveting is done by hand hammering. Countersunk head It is used where projection of the rivet head is to be avoided. Bifurcated rivet The shape of the head is shown in the figure...
. advantage and disadvantage of hot working metal . advantage and disadvantage of cold working of metal Working on metals This involves the manipulation of metals /materials when in the solid state Examples of working are forming, rolling, forging etc. Working processess can be classified Hot working Cold working Hot working Hot working is done at a suitable high temparature so that any damage to the grains is repaired. The temparature required varies from metal to metal. Examples of hot working Forging, rolling, extrusion et Advantage of hot working -hot working is relatively a low cost process -refinement of grain from cast structure is possible. -the scale givea some protection against corrosion during storage. After the process also the product will be in the fully annealed condition, suitable for further cold working. Disadvantage of hot working -poor surface finish is likely -dimensional inaccuracy is possible due to shrinkage on cooling -geometrical accuracy is possib...
Parts of a vernier calipers A vernier caliper is a precision measuring instruments. It is used to measure up to an accuracy of 0.02mm.The parts of a vernier caliper fixed jaws(1 and 2) are parts of the beam scale. One jaw is used for taking external measurements, and the other for internal measurements. Movable jaws(3and4): movable jaws are part of the vernier slide. One jaw is used for external measurements, and the other for internal measurements Vernier slide(5) :A vernier slide moves over the beam and can be set in any position by means of a spring loaded thumb lever beam(6): The vernier slide, and the depth bar attached to it, slide over the beam. The graduation on the beam are called the main scale division. depth bar(7): The depth bar is attached to the vernier slide and is used for depth measurement. Thumb lever(8): The thumb lever is a spring loaded lever which helps to set the vernier slab in any position on the beam scale. vernier scale (9): The vernier scale is ...
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