Ingot Selection for Open Die Forging: Mark, Shape and Hot Top
How to select a forging ingot for open die forging: work back from finished weight, then choose mark, shape, hot top and grade.
Start from the finished part
Take the finished weight and add machining allowance, scale loss and the head and bottom crop. That gives the usable body weight you need from the ingot.
Choose the mark
Pick the smallest ingot mark whose usable body gives the weight and the reduction your press can deliver. The size chart lists each mark with its dimensions and weight with hot top.
Choose the shape
Square for carbon steels and moderate alloys, fluted for crack-sensitive alloys and heavy weights, round for rings and discs.
Choose the hot top and grade
Over imposed or semi inserted hot top, depending on the mark. Then the grade: through hardening for shafts, case hardening for gear blanks, chrome-moly for pressure parts.
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