SHEET METAL AND CHARACTERISTICS INTRODUCTION Some of the

SHEET METAL AND CHARACTERISTICS

INTRODUCTION • Some of the major industries in which sheet metal plays an important part are : a) Heating and air conditioning b) Aircraft c) Ship Building d) Steel furniture, cabinets

DEFINITION • Sheet Metal – is a generally applies to metals and alloys in sheet rolled to thickness ranging from approximately 0. 5 mm – 3 mm

SHEET METAL PROCESS • a) b) c) d) e) Sheet metal can be roughly divided into five phases: Planning and layout Fabrication Assembly Installation Repair and Maintenance

PLANNING AND LAYOUT • Are steps by which a flat pieces of sheet metal is formed into the finished product. • Specifically, through the use of tools and methods, pattern are traced or drawn on the flat sheet of metals in orders to serve as a guide for the operations to follow. • Drafting, layout and pattern development must be done care and accuracy.

FABRICATION • The flat sheet metal with the layout on its fabricated through a number of different operations. • Some of the more common operations are : v. Cutting v. Making seams v. Folding v. Turning v. Forming vbending

ASSEMBLY • Individual articles or parts , now shaped and formed, are connected in a number of ways. They must be: q. Punched q. Riveted q. Drilled q. Soldered

INSTALLATION, REPAIR & MAINTENANCE • Installation, repair and maintenance require a good working knowledge of the product, and often involve connecting skills such as drilling, finishing skills.

SHEET MATERIALS • A large quantity of sheet metal used is steel rolled into sheets of various thickness and then coated with zinc, tin or lead. • Others common metals and alloys which are rolled into sheets are : 1) Zinc 2) Copper 3) Aluminium 4) Stainless steel

CLASISFICATION OF SHEET METAL • Sheet metal can be classified into two distinct groups : a) Coated b) Solid

GALVANIZED SHEET METAL • Consists of soft steel sheets coated with zinc. • Usually the steel is dipped in the acid bath for cleaning, and then is dipped in a tank of molten zinc to coat the sheet. • However, the zinc is put on by electroplating process. • Electroplating process is distinguishable from galvanized coating because it gives and even, grey colour. • Is used principally for its ability to hold a painted surface.

SHEET GAGES • The thickness of metal sheets is designated by a series number called gages. • Each gage designated a definite thickness. • It is important to know how to read and use micrometer for determine gages.