The Series FS0304-C ORFS Cap Assembly Inserts, made from carbon steel and designed per SAE 520112 standards, are essential components used in conjunction with FS0318 Nuts for creating leak-free connections in hydraulic systems. These inserts are specifically designed for O-Ring Face Seal (ORFS) connections, providing a secure seal by compressing the O-ring against a flat face to prevent leakage. The durable carbon steel construction ensures strength and long-lasting performance, making them ideal for high-pressure applications where reliability and leak prevention are critical. These inserts and their corresponding nuts offer a cost-effective solution for fluid power systems that demand high-quality sealing capabilities.