MEDICION DE CONICIDAD ESTÁNDAR API 7-2 – DEFINICION/TOLERANCIAS/INSTRUMENTO DE MEDICION T Taper, expressed as millimetres of diameter per millimetre of length or inches of diameter per foot of length. 6.1.6 Taper tolerance The taper tolerance of rotary shouldered connections shall be as follows: a) pin thread: +0,0025 mm/mm to 0 mm/mm (0.030 in/ft (1/32=0,031) to 0 in/ft) average taper between first and last full depth threads; b) box thread: 0 mm/mm to 0,0025 mm/mm (0 in/ft to 0.030 in/ft (1/32=0,031)) average taper between first and last full depth threads. Methods for determining taper are described in 8.5. 8.5 Taper measurement 8.5.1 Taper errors For all threads of rotary shouldered connections, taper tolerances shall be expressed in terms of millimetres per millimetre (inches per foot) of thread and taper errors shall be determined accordingly. The measurements are made for a suitable interval of thread length and the observed errors shall be calculated to the millimetres per millimetre (inches per foot) basis. 8.5.2 Taper calipers The taper of threads shall be measured with an instrument having an accuracy of 0,010 mm (0.0004 in) or better within the measurement range used.