Maximize the performance and durability of your inboard boat's propulsion system with this premium Marine Grade Shaft Nut Set Kit, engineered for 1-3/8" shafting. Whether you're replacing old components or preparing for the season, this all-in-one set ensures a secure, worry-free fit you can trust. Crafted from marine-grade brass and stainless steel, this set is purpose-built to resist corrosion from saltwater and freshwater exposure, delivering dependable fastening in the toughest environments. Perfect for routine shaft maintenance, emergency repairs, or seasonal upgrades, this shaft nut kit is a must-have for any serious boater. What's Included: (1) 1"-8 Marine Grade Brass Heavy Nut (1) 1"-8 Marine Grade Brass Jam Nut (1) 5/16" Marine Grade Brass Key (1) 5/32" Stainless Steel Cotter Pin NOTE: Key may need to be fitted to shaft. Why Choose This Boat Shaft Nut Set? Engineered for strength, reliability, and ease of use, this set offers premium materials and a precise fit for 1-3/8" inboard shafts. From weekend warriors to full-time mariners, this is the reliable solution your propulsion system deserves. Ideal For: Inboard boats with 1-3/8" shafting Marine environments – saltwater or freshwater DIY boaters & professionals who demand durability and ease of installation Anyone replacing worn shaft hardware or assembling a backup repair kit ⚠️ Pro Tip: Buy 2 — It Never Hurts to Have a Spare!