This tool can be used for the automatic control of the breaking load and of the relative lengthening of the yarns. The movement of the cart is a “CRE” type one, and it is possible to use different loading cells between 5 and 20 Kg to make the measurement of the resistance of the tested yarn more precise. The tool’s precision is 1% on the full scale, both for the lengthening and for the loading charge and it is possible to set the length of the tester with increments of 1mm between a minimum of 100 to a maximum of 500 mm. Moreover, it is possible to vary the speed of the tests between 100 and 5000 mm per minute, adapting it to the type of test selected. The software has pre-set parameters to execute the tests according to the existent normative, in order to make the setting of the instrument easier. The repositioning of the chart for the traction is effectuated at the highest speed in order to diminish the testing times. Thanks to the use of pneumatic clamping and of a mechanic controlled by a computer (not included), it is possible to mount even 20 yarn reels and effectuate even 1000 tests on each reel. In order to make the tests more reliable in time, it is possible to calibrate automatically the Tenatex using a certified optional load.