Question

Skim bob is attached to

• A. Along the runner
• B. Ingates
• C. Risers
• D. Pouring cup

Hint:

To improve casting quality, always ensure proper placement of skim bobs along runners to trap slag and floating impurities effectively.

Answer 1

The Correct Option is A

A skim bob is a type of sand trap used in the gating system of a casting process. It is attached along the runner and serves to trap impurities such as slag, oxides, or floating debris in the molten metal before it reaches the mold cavity. By placing the skim bob at an appropriate location along the runner, the flow of molten metal is directed such that lighter impurities are skimmed off and trapped, thereby preventing their entry into the final casting. This results in higher quality castings with fewer inclusions and surface defects.