Big Horn 19054C 8-Inch Inside Caliper Big Horn inside calipers are great for gauging the inner diameter of an opening and then transferring that measurement to a ruler The forged steel legs on this caliper feature hardened points for precise marking of the work piece An adjusting screw has a self-seating washer and nut to permit quick and positive adjustment Hardened and tempered bow springs and fulcrum spools assure uniform tension without side play while using this inside caliper Our inside calipers are frequently used in conjunction with precision rulers for the most accurate measurement transfer