You need every single part in the sequence to extract the final file. If one part is missing or corrupted, the extraction will fail with an "Unexpected end of archive" error. 2. Pre-Extraction Checklist
You do need to extract each part individually. The software is designed to recognize the sequence automatically. What is multipart archive - GitHub Gist 101013-451-carib-high-1.part3.rar
When dealing with files from unknown sources, especially those with potentially obscure or proprietary names: You need every single part in the sequence