In a strip of collated fasteners, each having a shank and a head, a carrier molded from a polymeric material has a sleeve for each fastener. Each sleeve has an annular portion and a breakable portion, which breaks into two segments as the fastener gripped by such sleeve is driven. The breakable portion, which is notched at one end, has a pair of similar, laterally opposed, outwardly opening, continuously curved concave recesses with open windows, from which portions of the fastener shank emerges. In a fastener-guiding tool, parallel ribs of a guiding device fit into such recesses, into close proximity with the emerging portions, so as to guide the strip between such ribs.