The Series 9019 Straight Male BSPP x Female Metric hydraulic adapters, made of carbon steel, connect British Standard Pipe Parallel (BSPP) male fittings with female metric fittings, commonly used in fluid power systems. BSPP connections are similar to NPSM but have a different thread pitch and sealing method, requiring thread sealant to prevent leaks. The seal is made by using metal-to-metal angled surfaces or a combination of metal and an O-ring. BSPP male connectors are comparable to NPSM male, but with different thread pitches, and the female swivel BSPP seals on the cone seat of the male connector. BSPT connections, which are tapered, are similar but not interchangeable with BSPP due to their sealing methods. Metric adapters, conforming to ISO 9974, ISO 6149, and DIN 7631 standards, can resemble BSPP but have different threads. Care must be taken to identify metric threads, as they share characteristics with British threads. The most notable difference is that DIN 7631 metric threads have a 30° chamfer on the male thread, similar to BSPP threads, while variations in sealing surfaces can make identification tricky. To identify metric thread size, a caliper reading of the thread's outer diameter can give an accurate measurement in millimeters.