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Sierra 18-3721-9 Stainless Steel Locknut (5Pk) Replaces 11-34933 - MW

SKU SIE-18-3721-9 MFR Sierra Marine (MW)

Express
Toronto, ON Vancouver, BC NJ, Warehouse FL, Warehouse
"Express" items are automated and typically shipped out the next available business day and delivered within 4 days.
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Sierra 18-3721-9 Stainless Steel Locknut for Mercury & Mercruiser Engines - 5 Pk

Sierra high-quality engine parts are designed to meet OEM specifications. Stainless Steel locknuts with nylon inserts.

Thread Size: 7/16" or 11.1mm - 20

  • For MCM inner transom studs and prop nut for Mercury 39, 60 (1968 & newer, 8 spline)
  • For MR/Alpha engines

Interchangeable with:

  • GLM
    • 21170
  • Mallory
    • 9-72004
    • 9-72004-10
  • Mercruiser Stern Drive
    • 11-29241
    • 11-24648
    • 11-21298
    • 11-22178
    • 11-82671015
    • 11-33962
    • 11-34933
  • Mercury Marine

WARNING: Cancer and Reproductive Harm - P65Warnings.ca.gov

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LibertyMarineUSA supplies marine and RV parts and accessories from trusted U.S. manufacturers and proven, quality-approved imported manufacturers. We focus on dependable, quality-tested products from reliable sources, so you can maintain, repair, and outfit your boat or RV with confidence.

Our goal is simple: to deliver the best quality marine parts you can count on. We focus on dependable service, fast shipping, and proven products that are either American-made or American-tested and approved for quality and reliability.