Pin Breaker

PIRA: 4A30.30

There are two ways to break a pin with the pin breaker apparatus: either by heating or by cooling.

In the first case, the pin is inserted into the hole in the expansion bar between the two walls, and the position of the bar is adjusted so that the pin is pressed gently against the wall.  The large hand nuts at the end opposite the pin hole are used to make such adjustments to the bar.  Now, when the burner is lit, the bar will heat and expand, pushing the pin harder and harder against the wall, until finally it is broken.

In the second case, the bar is heated first so that the pin can be placed in the other hole, on the other side of the wall.  Then the flame is turned off, and the bar cools.  As it contracts, the pin is pulled with greater and greater force into the wall, eventually causing it to snap.