Your Mercury deserves better than cheap aftermarket parts that fail after one season. This genuine NUT, (M6) Stainless Steel delivers the reliability your engine was built for.

Manufactured to strict Mercury Marine quality standards, this component ensures reliable operation across all engine RPM ranges. Part number 400212 is manufactured to exact Mercury Marine factory specifications for precision installation and optimal performance. Constructed from premium marine-grade materials designed to withstand harsh saltwater and freshwater environments.

Factory parts exist for a reason — they work. Part 400212 undergoes rigorous Mercury Marine quality testing that aftermarket manufacturers skip. The result? Reliable performance season after season.

Compatible Mercury Marine Engines

FITS: 10HP MARINER, MERCURY (MAGNUM, MARATHON, SEA PRO)

• Fits MARINER, MERCURY 10HP engines
• Compatible HP: 10HP
• Model types: MAGNUM, MARATHON, SEA PRO
• Covers 24 serial number ranges
• Configurations: Outboard
• OEM genuine Mercury Marine part

COMPLETE SERIAL NUMBER COMPATIBILITY:

10HP Models

• 10HP MAGNUM (Mariner): 0D038000-0D279999, 0D281000-0G760299, 0G760300-0T979999, 0P017000-0P325499, 9596000-9792199, 9792200-0P016999
• 10HP MARATHON (Mariner): 0D038000-0D279999, 0D281000-0G760299, 0G760300-0T979999, 0P017000-0P325499, 0T980000-0T999999, 9596000-9792199, 9792200-0P016999
• 10HP OUTBOARD (Mercury)
• 10HP SEA PRO (Mercury): 0D038000-0D279999, 0D281000-0G760299, 0G760300-0T979999, 0P017000-0P325499, 0T980000-0T999999, 9596000-9792199

Need help finding your serial number? Check our serial number location guide for step-by-step instructions on locating it on your Mercury engine.

Verification & Support

Want to verify compatibility for part 400212? Use our parts finder tool for instant confirmation. Still have questions? No problem – use the contact buttons at the bottom of this page to reach us by text, call, or email

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