CLASS NOTES FOR
Manufacture products for individual use. These use international
standards. It reduces cost, increases availability & improves quality.
Definition of manufacturing
Manufacturing is a sequence of effective and economical processes. It converts raw material into a useful finished product as per National or International standards. Manufacturing is wealth producing while a service sector is wealth consuming. Steel industry and semi-conductor industries name manufacture as fabrication.
Definition of a product
Product is an item. It has certain specifications. This serves a useful purpose.
TYPES OF PRODUCTS
1. Tangible Products
Tangible products are ready to use after manufacturing. Burger, book, Shoe, jewelry, Bulb, tube light, mobile phone, pen, chocolate, computer, shirt etc. are tangible products.
2. Intangible Products
Intangible products are not ready to use directly after manufacturing. Software, insurance, trademark, service contract, lease agreement are some of intangible products. Mechanical engineering involves the production of only tangible products.
MAIN MANUFACTURING METHODS
The type of manufacturing process depends on the characteristics of raw material available and the final finished useful product required.
Definition of Casting, Forming, Joining, Machining and Rapid Prototype Methods of Manufacturing
DEFINITION OF CASTING
Casting is a one step high temperature process. It uses molten metal to make a product of specific shape and size. Casting makes uses molds (cavity) to hold the molten material in a desired shape until it gets solidified.
DEFINITION OF FORMING
Forming uses relative low temperatures as compared to casting. It uses force to make a product of specific shape and size.
DEFINITION OF JOINING PROCESS
Most of the final products consist of many parts. Assemble these parts to form the final useful finished product.
DEFINITION OF MACHINING PROCESS
Machining is the process of controlled removal of material from a work piece. It creates a specific shape or specific surface finish.
DEFINITION OF RAPID PROTOTYPING
Casting produces useful final finished products using a software.
COMPARISON BETWEEN WELDING AND RIVETING
Advantages of Welding
Firstly Welding is fast, saves time in manufacture and assembly.
Secondly Welding provides more strength.
Thirdly Welding produces light structures.
Disadvantages of Welding
Welding is costly. Welding equipment is costly. It requires highly skilled worker.
Deposited metal is very costly
Firstly welded joints do not have damping capacity.
Secondly welded parts have excessive deflection.
Thirdly welded joints replaced riveted joints. Use riveted joints in high temperature applications.