Trimming Die-castings
At the end of each run the operators of the machines go over their work, breaking the castings from the sprues and throwing out all that are defective. No matter how carefully the die-casting molds have been made, there is always a certain amount of trimming to be done on the finished die-castings, on account of the crevices left in the die for air vents, or which exist from improper fitting of the parts of the dies. These “fins,” as they are called, are trimmed by hand operators in a special department. A general view of this trimming room is shown in [Fig. 28]. Usually it is sufficient to scrape these fins off with a scraping knife, but if the casting is especially difficult to produce, so that a large opening is required to admit the metal, it is sometimes necessary to trim unusually thick sprue sections by filing. [Fig. 29] illustrates the method of trimming such die-castings on a filing machine.
Fig. 30. General View of E. B. Van Wagner Co.’s Die making Department
Fig. 31. A Typical Die-casting Mold