Features These outside spring and firm joint calipers are used for taking indirect measurements. They are adjusted until their legs make contact with an external diameter, groove, or other feature and locked in place. Then the distance between the legs is measured with a ruler or high-precision gauge. These calipers are commonly used in metalworking, machining, and woodworking applications. Range / 0 in to 12 in/0 mm to 300 mm Joint Type / Spring Maximum Measurement / 300 mm, 12 in Maximum Measurement - Inch / 12 in Maximum Measurement - mm / 300 mm Minimum Measurement - Inch / 0 in Minimum Measurement - mm / 0 mm Nut Type / Quick-Spring Tip Type / Solid Points Caliper Material / Steel Leg Style / Flat