Print, Photographic
Black and white photographic print mounted on fabric depicting many women operating lathes at the Champion Spark Plug Co.
Caption reads: Photograph 12
After the blanks are properly dried they are shaped into cores. This is done on special lathes shown in this photograph. The dried blank is placed on a spindle in such a way that it revolved and at the same time it is brought down against a rapidly turning carborundum grinding wheel which cuts away the clay blank. Each raise on the face of the wheel makes a corresponding groove around the outside of the blank, so that the shape of the wheel is exactly the reverse of that to which the blank is to be ground. Using the dry grinding method of shaping the cores permits of very accurate sizing, as all drying shrinkage has been eliminated.
