A sleeve interference fastener including a conformable sleeve, wherein the conformable sleeve is comprised of at least one first material having a hardness of X, and a pin member, wherein the pin member is comprised of at least one second material having a hardness of Y, wherein X is sufficiently less than Y so that, in an installed position of an interference fit, at least a portion of the at least one first material of the conformable sleeve conforms to a contour of an inner surface of a hole of a composite structure so as to create a continuous electrical contact at an interface between the inner surface of the hole of the composite structure and the conformable sleeve.