This apparatus has an adjustable stationary clamp 25 mm in width for holding one end of the specimen in a fixed position, and a similar reciprocating grip for clamping the other end of the specimen.
The axis of the movable part is in the same straight line as that of the stationary part so that the reciprocating motion is in the same plane as the centreline between the grips. The clamps are 28.5 ± 2.5 mm apart in the open position and 9.5 mm ± 1.0 mm apart in the closed position.
It is equipped with a cam that actuates the reciprocating part. The movable part is driven by a constant-speed motor at the frequency of 340 flexes / min to 400 flexes / min.
The specimens are arranged in 2 equal groups so that one group is being bent while the other is being straightened, thus reducing the vibration in the machine. The clamps can fix the specimen firmly and enable individual adjustments to be made to each specimen.