## Die opening force

Force which acts on the die halves during the casting process due to the metal pressure (Figure 1). The die opening force Fs is the product of the two factors projected area As and specific casting pressure pm (final pressure in die casting and low pressure die casting) and is calculated according to Eq. 1 as follows:

Eq. 1:
$F_s\lbrack kN \rbrack = \frac{A_s\lbrack cm^2 \rbrack \cdot p_m\!\lbrack bar \rbrack }{100}$

The die locking force Fz must be larger than the die opening force so that the die remains closed during casting and the metal does not squeeze or squirt out and it can be ensured that the casting measurement tolerances are met. Therefore, when calculating the die locking force a safety factor k is added to the die opening force which is chosen as follows:

$k = 1,25\ bei\ Formen\ mit\ Schiebern$
$k = 1,1\ bei\ Formen\ ohne\ Schieber$

The die locking force is therefore calculated according to Eq. 2:

Eq. 2:
$F_z = k \cdot F_s$