A thread gauge inspection apparatus includes a receiving member to hold a reference thread gauge and a motor to bi-directionally rotate the reference thread gauge. A counter counts a number of turns the reference thread gauge is rotated by the motor, and a torque monitoring device monitors the torque produced by the motor as the reference thread gauge is rotated. A controller, when the monitored torque exceeds a predetermined value, causes the motor to stop rotating the reference thread gauge and causes the counter to stop counting the number of turns the reference thread gauge is rotated. The controller compares the count produced by the counter with an inputted specific turn count and indicates the thread quality of threaded hole or a threaded stud passed inspection when the count produced by the counter is equal to the inputted specific turn count.

A three-roll thread gauge for measuring interior threads includes a fixed gauge roll and two movable gauge rolls. The motion of the two movable gauge rolls is constrained so that the interior angles of a triangle defined by the three gauge rolls are equal for each position of the first and second gauge rolls when the three gauge rolls are in engagement with an interior thread. The motion is constrained by reverse sine bars that limit the motion of first and second tables to which the first and second gauge rolls are attached.

A three-roll thread gauge for measuring interior threads includes a fixed gauge roll and two movable gauge rolls. The motion of the two movable gauge rolls is constrained so that the interior angles of a triangle defined by the three gauge rolls are equal for each position of the first and second gauge rolls when the three gauge rolls are in engagement with an interior thread. The motion is constrained by reverse sine bars that limit the motion of first and second tables to which the first and second gauge rolls are attached.

Embodiments of the present disclosure provide an adjustable diameter step pin apparatus. The adjustable diameter step pin apparatus includes a body element and a head element having a thumb screw portion and a threaded portion. The body element includes a plurality of threaded finish structures. The body element may be configured to receive a collet along a longitudinal slot of the adjustable diameter step pin apparatus. The thumb screw portion may be configured to rotate to alter the collet and the threaded portion may be configured to engage with the plurality of threaded finish structures when assembled with the body element. In an embodiment, the head element may be rotatable to engage the threaded portion of the head element into the plurality of threaded finish structures to alter the collet while keeping the body element sturdy.

Embodiments of the present disclosure provide an adjustable diameter step pin apparatus. The adjustable diameter step pin apparatus includes a body element and a head element having a thumb screw portion and a threaded portion. The body element includes a plurality of threaded finish structures. The body element may be configured to receive a collet along a longitudinal slot of the adjustable diameter step pin apparatus. The thumb screw portion may be configured to rotate to alter the collet and the threaded portion may be configured to engage with the plurality of threaded finish structures when assembled with the body element. In an embodiment, the head element may be rotatable to engage the threaded portion of the head element into the plurality of threaded finish structures to alter the collet while keeping the body element sturdy.

A digital threaded plug gauge, including a barrel, a sleeve disposed around the barrel configured to move up and down with respect to the barrel, the sleeve including a serrated rod having serrations thereupon, a spring attached to the serrated rod to allow for elastic functionality of the serrated rod as the sleeve moves up and down with respect to the barrel, and a sprocket disposed within the sleeve to cause the serrations of the serrated rod to catch upon the sprocket to allow the digital threaded plug gauge to obtain a depth reading corresponding to a distance that the sleeve has traveled, a display unit to display a distance that the sleeve has traveled, and a caliper circuit board to sense a distance that the sleeve has traveled with respect to the barrel, thereby allowing the display unit to display the distance that the sleeve has traveled.

A digital threaded plug gauge, including a barrel, a sleeve disposed around the barrel configured to move up and down with respect to the barrel, the sleeve including a serrated rod having serrations thereupon, a spring attached to the serrated rod to allow for elastic functionality of the serrated rod as the sleeve moves up and down with respect to the barrel, and a sprocket disposed within the sleeve to cause the serrations of the serrated rod to catch upon the sprocket to allow the digital threaded plug gauge to obtain a depth reading corresponding to a distance that the sleeve has traveled, a display unit to display a distance that the sleeve has traveled, and a caliper circuit board to sense a distance that the sleeve has traveled with respect to the barrel, thereby allowing the display unit to display the distance that the sleeve has traveled.