四、形体控制框(Feature Control Frame)
1. 目的(Purpose)
2. 符号(Symbol)
3. 基准形体参考(Datum Feature References)
4. 材料原则对实体基准参考的影响(Material Condition on FOS Datum Reference)
5. 基准次序和材料原则的影响(Datum Sequence and Material Condition)
6. 形体控制框类型(Types of Feature Control Frame)