Pieces of rivet steel, heated uniformly to a low cherry red, and cooled in water of 82° Fahrenheit, must stand bending double in a press to a curve of which the inner diameter is equal to the diameter of the bar tested.

Bending cold without fracture in the manner shown in Fig. 1, where the line AB equals one diameter of the rivet.

Bending double when hot, and hammered till the two parts of the shank touch in the manner shown in Fig. 2 without fracture.

Flattening of the rivet head while hot in the manner shown in Fig. 3 without cracking at the edges. The head to be flattened until its diameter is two and a half times the diameter of the shank.

Fig. 1.

Fig. 2.

Fig. 3.

The shank of the rivet to be nicked on one side, and bent over to show the quality of the material.