Mix mayonnaise and red pepper in large bowl. Add crabmeat, 3 cups of the cracker crumbs, pimientos and onion; mix well.
Shape crabmeat mixture into 48 patties, using 1/3 cup of the crabmeat mixture for each patty. Coat on both sides with remaining 3 cups cracker crumbs.
Cook patties in butter on medium heat for 5 to 6 minutes on each side or until heated through and golden brown on both sides.