The burglar plate is a laminated sheet. In this picture you can see the layer joints in the 5 ply burglar plate. These pieces probably started out as 1.25” but were machined to 1” to be bolted together to create the door and door jamb on a Mosler screw door safe.

At first look I thought Mosler’s machining quality was poor but after learning of the layers of different hardness of the material, I could understand why it would have an uneven finish.
