When sourcing pneumatic cylinder joints, you must prioritize thread size and type (e.g., Metric, G, NPT, or PT) to ensure a leak-proof connection. Material selection is critical; nickel-plated brass offers excellent corrosion resistance, while stainless steel (304/316) is mandatory for food-grade or highly corrosive environments. Additionally, verify the maximum operating pressure (typically up to 1.0-1.5 MPa) and temperature range (-20°C to +80°C for standard NBR seals, or higher for Viton/FKM seals) to match your specific industrial application.