When procuring H7 reamers, the most critical factor is the tolerance class. An H7 rating indicates a specific precision fit according to ISO standards, typically used for high-quality engineering holes. You must verify the material composition, such as HSS (High-Speed Steel), HSS-Co (Cobalt), or Solid Carbide, depending on the hardness of the workpiece. Additionally, consider the flute geometry (straight flutes for through holes vs. spiral flutes for blind holes) and the shank type (straight or Morse taper) to ensure compatibility with your CNC or manual machining equipment.