How can we delete materials permanently from Material master?
Use transaction MM70 - Material Master->Other->Reorganization->Material->Choose.
Build variant with selection range of material master records to be selected for deletion and maintain
Use transaction MM71 - Material Master-> other-> Reorganizationn-->Material->Reorganization
Build a second variant
Maintain run parameters and execute.
It is also important to remove the records manually from info record, POs, PRs, reservation etc
for successful deletion of the material.
Reward if helpful...