Astro 7415 15-Piece 1/2" Drive Twist Damaged SAE/Metric Fastener Remover Socket Set 15 Piece 1/2" Drive Twist Damaged SAE/Metric Fastener Remover Socket Set; Spiral and tapered internal splines are designed to grip the perimeter of any damaged or rusted nut, stud, pipe nipple or bolt Place the twist socket on, and twist the damaged fastener off; No more pounding, chiseling or torching Safe and fast removal of damaged fasteners and easy removal of the fastener from the twist socket Made of top quality CrMO steel provides good wear resistance and durability Kit includes: 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 3/4", 13/16", 7/8", 15/16", 1", 1-3/16" and 1 piece Knock-up Bar