Table 3-4. Lintel sizes for 8- and 12- inch walls
3-28. Double-Angle Steel. If you are using a double-angle steel lintel, it should be 1/4 in thick. This
makes it possible for the two-angle legs to project up into the brick to fit exactly into the 1/2-inch joint
between the face and backing-up ties (Figure 3-32).
Figure 3-32. Double-angle steel lintels