Pattern Pattern Materials Pattern is duplicate of the component manufactured by casting material. Pattern Materials Wood Metals Plasters Plastics and Rubbers Waxes

Types of Patterns Types of Patterns Used in Sand Casting: (a)solid pattern (b)split pattern (c)match‑ plate pattern (d)cope and drag pattern (e)gated pattern (f)loose piece pattern (g)sweep pattern (h)shell pattern

Solid Pattern (Single Piece)

Split Pattern

Cope and Drag Pattern

Match Plate Pattern

Pattern Allowances Pattern Allowances 1.Shrinkage allowance 2.Draft allowance 3.Finish allowance 4.Shake allowance 5.Distortion allowance

Core and Core Making Core is part used in casting processes to produce internal cavities. Requirements of Core There must be adequate strength for handling. In the hardened state it must be strong enough to handle forces of casting. Permeability must be very high to allow for the escape of gases Good refractoriness is required as the core is usually surrounded by hot metal. A smooth surface finish A minimum generation of gases during metal pouring.

Core Making Process Purpose of Core For hollow casting Used to strengthen the moulds Core Making process Core Sand Preparation Core Making Core Baking Core Finishing

Types of cores i)According to the shape and position of the Core Horizontal, Vertical ,Hanging ,Balanced ii)According to the state or condition of core Green Sand , Dry Sand iii)According to the type of core hardening process employed Hot box , Cold set, Cast able Sand, Oil-No-Bake Process

Core Boxes Core box is basically a pattern for making cores Core boxes are employed for ramming core in them Core boxes impart the desired shape to the core sand Types of core boxes Half core box Slab or Dumb Core box Gang Core Box Loose Piece Core Box