Mercury - Cotter Pin Swivel Bracket Hardware Stainless Steel 93861. Overview. Every boater knows the big parts get all the glory, but it's the small, unseen hardware that quietly keeps everything moving the way it should. The Mercury 93861 Cotter Pin is one of those unsung heroes. When you're working with a high-horsepower TwoStroke engine, you need absolute confidence that every component-right down to the smallest pin-is built to last. This little piece of stainless steel delivers that peace o