Material Stock Alignment and Cross-section Determination
When costing a part, aPriori automatically determines the most likely stock form and alignment direction. To do this, it analyzes the geometry of the part and evaluates potential stock axis directions and cross-sections from these directions. To view the chosen stock cross section, click the 
Stock Form and Alignment button in the Component Viewer tool bar.
Stock Form and Alignment button in the Component Viewer tool bar.To choose a different stock form or align the stock differently, use the Stock Form and Alignment tool in the Component Viewer. For more information, see the "Defining stock form and alignment for the Stock Machining and Bar &Tube process groups" section of the aPriori User Guide.
Note Changing material stock form and alignment may affect material utilization.
Round parts are generally assigned a round cross-section (allowing the selection of round stock). But for parts that are, roughly speaking, flat and round, geometry extraction assigns a rectangular cross-section (and may select plate stock). Parts are considered flat and round, in this sense, if both the following hold:
• Part’s round cross-section diameter is greater than or equal to the value of the site variable maxRoundStockDiameterMm (304.8mm in starting points).
• Ratio of part thickness to round cross-section diameter is less than or equal to the value of the site variable maxRoundStockAspectRatio (0.2 in starting points).
If either of these site variables is -1, aPriori may select the round cross-section rather than the rectangular one.
In starting point VPEs, plate stock is auto-selected by aPriori only if the part width is greater than 142.4mm and the height-to-width ratio is less than 0.25. VPE administrators can customize these thresholds with the cost model variables minPlateTriggerWidth and maxPlateTriggerHeightOverWidth.