Fix-A-Thred offers solutions for damaged threads Alcoa Fastening Systems' line of Fix-A-Thred stainless steel helical wire inserts are available in sizes ranging from #8 to 1-1/2 in inch course and inch fine sizes, and from M3 to M24 in metric course and metric fine sizes. The line also includes all necessary screw thread insert taps, installation tools, and a number of kits that include a selection of inserts and related tools.