A new processing technique, called in this study as high-pressure sliding (HPS), was developed as a process of severe plastic deformation (SPD). It is then demonstrated that HPS can be used for grain refinement of metallic sheets with a rectangular shape which was difficult with a conventional high-pressure torsion utilizing disk samples. Application of HPS to pure Al (99.99%) showed that the grain refinement is achieved with the extent similar to other SPD techniques.