53 of the side wall protuberances 20 this is illustrated in fig5 where it can be seen that each of the threads 46 of the fastener screw 42 is disposed deeply within each of the grooves 18 between the side wall protuberances 20 and each of the threads 46 is disposed proximate to the squared off edges 22 of the side wall protuberances 20 but none of the threads 46 of the fastener screw 42 impinge upon the squared off edges 22 of the side wall protuberances 20 to such an extent that the side wall protuberances 20 are deformed with respect to their squared off configurations a typical fastener screw 42 for use with a framing member 10 comprises side walls and with a height a of about 0 500 inches is a screw 42 having threads 46 which have a thickness i which is typically between about 0 035 inches and about 0 045 inches most typically about 0 040 inches the threads 46 are typically spaced apart by a distance j of between about 0 0700 inches and about 0 0750 inches most typically about 0 0725 inches the threads 46 protrude away from the central member 54 of the fastener screw 42 by a distance k typically between about 0 0600 inches and about 0 0625 inches most typically about 0 06125 inches the diameter 1 of the central member 54 of the fastener screw.