Screw Filler Plugs

The screw filler plug is a vital sealing fastener used to block ports in engine oil pans, transmission housings, brake systems, and hydraulic pipelines across automobiles and motorcycles. It effectively prevents leaks of oil and hydraulic fluid while blocking contaminants from entering the system, ensuring stable pressure and fluid cleanliness. This screw filler plug is adaptable to various powertrain, chassis, and motorcycle engine applications, including commercial trucks, passenger vehicles, and new energy models, making it an indispensable protective component.

Produced in compliance with ISO 898-1 Gr.8.8, GB/T 3098.1, and SAE J429 Gr.8 standards, the screw filler plugs is available in three material series: 45# carbon steel for general strength, 304 stainless steel for superior corrosion resistance in humid/high-temperature conditions, and copper alloy for excellent sealing and thermal conductivity in precision hydraulic systems. All variants undergo pressure seal testing, remaining leak-free under 10-30 MPa, meeting the stringent safety requirements of diverse hydraulic systems.

Our screw filler plugs range includes thread sizes from M8 to M30 and lengths from 6mm to 50mm, with head options such as hex socket, external hex, and countersunk. Sealing is achieved via metal-to-metal hard sealing or integrated O-ring designs. Threads are precision-cut to 6H grade for a tight fit. Custom surface treatments like fluorocarbon coating or Dacromet are available for resistance to oil, high temperature, acids, and alkalis. We can develop custom screw filler plugs based on client drawings to fit both standard and non-standard port configurations.

With a monthly output exceeding 1.5 million units, we ensure fast delivery for bulk orders and custom production. A strict 12-step quality control process includes dimensional checks, pressure seal tests, and corrosion resistance evaluations, resulting in a pass rate above 99.9%. We provide tailored packaging and logistics for hardware wholesalers and automotive parts suppliers, backed by technical support, making us a trusted long-term partner for hydraulic system sealing solutions.