Gas Holes Vs. Shrink Holes

Basic Aluminum Casting Co.

For over half a century The Basic Aluminum Casting Company has been a privately held, financially solid die casting company with a professional integrity matched by few in today’s industry.diecasting

At The Basic Aluminum Casting Company, we bring quality die casting with delivery and pricing achieved through a sound business organization. Centrally located in Cleveland, Ohio, we’re easily accessible across the Midwest and the entire United States. Occupying over 55,000 square feet at our plant, Basic has serves the transportation and general manufacturing industries and beyond! The Basic Aluminum Casting Company can be best described as an engineering company with one simple trait – creating die cast products  from listening and understanding our customer’s needs.  A strong commitment to that and a focus on quality has enabled us to continue to be one of the best and oldest names in the industry.


Die Castings are subject not only to air inclusions but also shrink holes and gas holes.

Shrink holes are caused primarily by insufficient feeding of metal to the casting. For instance, when the metal in the gate freezes before the metal in the die casting has had a chance to solidify, volume changes attending the liquid shrinkage cannot be made up by supplying reserve liquid metal through the gate, and shrink holes are apt to occur. Another condition that contributes to the formation of shrink holes is premature freezing of the metal in an intermediate section between the gate and the section in distress.

Gas holes are another type of defect in die casting. They are distinguishable from shrink holes in that they are smooth and round, whereas shrink holes are ragged and irregular in shape. Gas holes are caused by the release of gasses or vapors from the metal as it is cast.These defects occur when the metal is not scavenged after it has been exposed to humid atmosphere and fuel gases in the melting or holding furnace.

 

Doehler, H.H. Die Casting. New York,New YorkMcGraw-Hill Book Company Inc., 1951. Print.