A windowless multi-fiber ferrule including a ferrule body. The ferrule body includes a plurality of outer slots. The ferrule body defines an inner passage that extends through a length of the ferrule body from a front end to a rear end. The inner passage includes a main chamber and a row of parallel fiber bores. The ferrule body includes a first and a second major side which each define a plurality of slots. The ferrule body includes ferrule walls which are located between the main chamber and the major sides. The ferrule walls have a first thickness at the outer slots and a second thickness at the regions between the outer slots which is thicker than the first thickness. The main chamber includes sink locations adjacent the regions between the outer slots.