Que 1: Enlist the tools helpful tin smithy shop. Discuss at least three in brief.
Ans: The common hand tools used in sheet metal work are, steel rule, wire gauge, dot punch, trammels, scriber, ball peen hammer, straight –peen hammer, cross peen hammer, Mallets, Snips and Soldering Iron etc.
Snips: Hand shear or snips are used to cut sheet metal. Although there are many types, the sheet metal works generally use straight snips and curved snips
a. Straight snips: Straight snips have straight blades and are used for cutting along the straight lines and for trimming edges.
b. Curved snips: Curved snips has a curved blade and used for cutting circles and irregular shapes
Bench shears: Bench shear is used for cutting thick sheets. The lower fixed blade is firmly secured by bracket at bottom. The movable blade is pivoted at the rear end; the hand operating lever is attached to the front end of movable blade link mechanism.
Stakes: Stakes are made of steel and forged in a variety of shapes and sizes. Its workingfaceismachined and polished to facilitate various operations such as bending, seamingor forming.The following types of stakes are mostly used.
a. Double seaming: These stakes has two horns and it is used to make doubleseamforvessels.
b. Blow horn: These stakes have two horn tapering norms and it is used to forming or seaming funnels.
c. Break horn: These stakes have a square tapered horn on one side and a round taperedhorn on opposite side. It is used for shaping round and square surfaces, bending edges ,and making corners.
d. Conductor stake: These stakes has two cylindrical horns having different diameters. It is used for forming pipes and cylindrical pieces.
e. Funnel stake: It is used for forming conical shapes and for making wire rings.
f. Hatchet stake: It has a horizontal sharp straight edge and can be used for making straight sharp bends and for folding and bending edges.
Que 2: Discuss different sheet metal materials used in tin-smithy shop in terms of characteristic and usage.
Ans: Sheet metal work deals with the production of components in wide variety of shapes and sizes with the aid of tools or machines.
Galvanized Iron: It is a sheet of soft steel, which is coated with zinc. Zinc resists corrosion and improves the appearance of the metal galvanized iron in one of the least expensive metals and is used for making pans, buckets, ducts, gutters, tanks, boxes, etc.
Black Iron: It is an uncoated sheet of metal with bluish- back appearance. It corrodes rapidly is not expensively due to difficulties of soldering the block iron sheet are used for parts that are to be painted.
Tin plate: Tin plate is an iron or steel coated with pure iron. It has very bright silver appearance and is used for food containers, cans, pans.
Stainless steels: It is an alloy steel possessing corrosion resistance. General type stainless steel contains 18 % chromium and 8% nickel. This steel is commonly known as 18-8 stainless steel. These are available various sizes and thickness. It is widely used for food containers, dairy equipment.
Copper: It has reddish color and possesses good malleability, ductility and resistance to atmospheric corrosion.
Aluminum: Sheet aluminum is never pure aluminum and it is always allowed with small quantities of copper silicon, magnesium, and iron.
Que 3: Write a short note on various sheet metal joints.
Ans: Various types of joints are used in sheet metal work to suit the varying requirements. Some commonly used sheet metal joints and folded edges are shown below. These are self secured joints, formed by joining together 2 pieces of sheet metal and using the metal itself to form the joint.
Que 4: To Prepare a Tin Smithy job as per the given drawing.
Ans — WORKSHOP WORK