When sourcing used tables, prioritize structural integrity and material durability. Check for solid wood (oak, maple, or walnut) or high-pressure laminate (HPL) tops, as these withstand heavy commercial use better than veneer. Ensure the base is made of cast iron or heavy-duty steel to prevent wobbling. For outdoor use, verify the material is weather-resistant aluminum or treated teak. Always request the original manufacturer's specifications to confirm the load-bearing capacity (typically ≥200 lbs for standard dining).