CS Johnson Handy Clevis & Cotter Pin Assortment Kits offer the most common size clevis and cotter pins used on boats. The assortment for small boats has 46 styles of clevis and cotter pins ranging from 3/16 to 5/16 in. The one for for large boats has 36 different clevis and cotter pins, from 5/16 to 1/2 inch.