4Pcs Oxygen Sensor Nut Weld Bung Plug M18x1.5 O2 Sensor Adapter Curve Notched Nut Bung Stainless Steel Universal Auto Part

【Stainless Steel】 Made entirely from 304 stainless steel through one-piece drawing, it is heat-resistant and oxidation-resistant, capable of enduring high-temperature exhaust conditions over long periods. It resists corrosion from acidic and alkaline exhaust gases as well as moisture-induced rust, making it less prone to rust than ordinary iron nuts. It maintains its shape even under prolonged exposure to harsh exhaust environments. 【Standard Fine Thread】 Precision-machined with standard M18×1.5 internal thread, featuring uniform and smooth pitch that perfectly matches the majority of automotive oxygen sensor probes on the market. Offers optimal tightness during installation—resistant to stripping or slipping—and ensures a secure, gap-free seal. 【Curved Design】 One end features a flat, sealed surface, while the other has a curved notch design that provides convenient tool access, enabling quick tightening and removal even in confined engine bay spaces. The notch structure does not obstruct sensor wiring, preventing wire compression and wear, making it ideal for exhaust manifold and exhaust pipe modifications involving welding. 【Dedicated Accessory】 Suitable for use as an installation base for oxygen sensors in passenger cars, SUVs, motorcycles, and modified vehicles. Can be directly welded onto exhaust pipes or catalytic converter housings, serving as a universal component for OEM replacement, exhaust system upgrades, and repair applications.