PURPOSE: To double the weight of a balance thereby to reduce the size of a tester by providing a connector between a rotatable lever and a test piece so that a weight suspender is connected to the lever.

CONSTITUTION: In case the weighing tests are to be accomplished, a ram cylinder 11 is operated to raise a supporting plate 10 so that all balances 8aW8d are lifted to prevent their weights from being applied to a lever 2. Then, a motor 42 is started to move a bance weight 40. When the weight 40 abuts against the sensing lever of a limit switch 43, the motor 42 is stopped. Then, this motor 42 is started again to move the balance weight 40 in two directions. The piston system under its extended condition is gradually contracted so that a blade 5 of a lever 2 is used to suspend the balances 8aW8d in the specified order. Theus, the doubled weight is applied to a load cell 27.