When evaluating a Tube Bundles Factory, you must prioritize material compatibility and thermal efficiency. Key specifications include the tube material (e.g., Stainless Steel 316L, Titanium, or Copper-Nickel for corrosion resistance), tube diameter and wall thickness (to handle specific pressure ratings), and the pitch configuration (triangular or square) which affects heat transfer and cleaning ease. Ensure the factory provides TEMA (Tubular Exchanger Manufacturers Association) class designations (R, C, or B) to match your specific industrial application.