Outside Firm-Joint Caliper Range 0.037 in to 24 in 1 mm to 608 mm Joint Type Firm Maximum Measurement 457 mm 18 in Maximum Measurement - Inch 18 in Maximum Measurement - mm 457 mm Minimum Measurement - Inch 0.037 in Minimum Measurement - mm 1 mm Nut Type Solid Caliper Material Steel Leg Style Flat