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WBS is nothing but Work Breakdown Structure. It is mainly used in Project System (PS) module. Tcode: CJ20N. For any project defined we must have atleast one WBS. Within this WBS we can have networks. Networks are nothing but the series of activities. Material are used to perform the activities.
High Speed Steel (HSS): Provides good wear resistance and costs less than cobalt or carbide end mills. HSS is used for general purpose milling of both ferrous and non-ferrous materials. Cobalt (M-42: 8% Cobalt): Provides better wear resistance, higher hot hardness and toughness than high speed steel.