On a boat, even the smallest fastener can make the difference between rock-solid reliability and something working loose at the worst possible moment. The Mercury Marine Screw - 8M4501000 is one of those essential pieces of hardware - built to secure key components and hold tight through vibration, water exposure, and the constant stress of marine operation.. This isn't just any off-the-shelf screw. Precision-machined to meet Mercury's exact specs, it threads cleanly into place without risk of cross-threading or stripping. Its corrosion-resistant construction stands up to relentless salt spray, humidity, and the natural wear-and-tear that comes with life on the water. Whether it's part of a major assembly or anchoring a critical cover or bracket, this screw is designed to keep things right where they belong - trip after trip.. Why it belongs in your toolkit:. Genuine Mercury part - exact fit for select engines and systems. Marine-grade construction resists corrosion and thread degradat