A control ring and a method of using a control ring on fasteners can be used to verify a headed fastener having a band coating a fastener shaft. The ring comprises a cylindrical tubular body extending along an axis of revolution (B) and two opposite extremities. A first extremity includes two adjacent arc segments, each arc segment having an end wall extending in a plane perpendicular to the axis of revolution (B) of the ring, the planes of the two walls not being one and the same and axially offset from the first extremity. Each arc segment comprises at least one side wall extending over a radial plane going through the axis of revolution (B) of the ring. The width of an arc segment allows verifying a minimum band width, and the width of the two arc segments allows verifying a maximum band width on the fastener.

A control ring and a method of using a control ring on fasteners can be used to verify a headed fastener having a band coating a fastener shaft. The ring comprises a cylindrical tubular body extending along an axis of revolution (B) and two opposite extremities. A first extremity includes two adjacent arc segments, each arc segment having an end wall extending in a plane perpendicular to the axis of revolution (B) of the ring, the planes of the two walls not being one and the same and axially offset from the first extremity. Each arc segment comprises at least one side wall extending over a radial plane going through the axis of revolution (B) of the ring. The width of an arc segment allows verifying a minimum band width, and the width of the two arc segments allows verifying a maximum band width on the fastener.

A thread gauge, which allows to reliably know the time for replacement by visual checking and improves the predetermined dimensional accuracy of a thread product has a go-side thread measuring portion extending from one side of a shank portion coaxially with the shank portion or a not-go-side thread measuring portion extending from an other side of the shank portion coaxially with the shank portion, a wear checking gauge line having a predetermined length and a predetermined depth formed on male thread portions and female thread portions formed on the go-side thread measuring portion or the not-go-side thread measuring portion.

A thread gauge, which allows to reliably know the time for replacement by visual checking and improves the predetermined dimensional accuracy of a thread product has a go-side thread measuring portion extending from one side of a shank portion coaxially with the shank portion or a not-go-side thread measuring portion extending from an other side of the shank portion coaxially with the shank portion, a wear checking gauge line having a predetermined length and a predetermined depth formed on male thread portions and female thread portions formed on the go-side thread measuring portion or the not-go-side thread measuring portion.

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 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.