Embossed steel sheets

An embossed piece of sheet steel comprising:

• a piece of sheet steel having a first side and an opposing second side;
• a plurality of indentations formed on the first side of the piece of sheet steel in a pattern;
• and
• the pattern having equally spaced parallel rows and equally spaced perpendicular intersecting columns, the indentations of the plurality of indentations being positioned along each row at alternating intersections with the columns and each adjacent row having the indentations at alternating intersections offset by one column.

A method of forming an embossed piece of sheet steel comprising the steps of:

• providing a piece of sheet steel having a first side and an opposing second side,
• providing a rotating roller die having protrusions extending from a surface thereof for forming indentations in the first side of the piece of sheet steel, the protrusions of the roller die formed in a pattern along equally spaced parallel rows and equally spaced perpendicular intersecting columns, wherein the protrusions of the roller die are positioned along each row at alternating intersections with the columns and each adjacent row having the protrusions at alternating intersections offset by one column;
• providing a complemental roller die having protrusions extending from a surface thereof for forming indentations in the second side of the piece of sheet steel, the protrusions of the complemental roller die formed in a pattern along equally spaced parallel rows and equally spaced perpendicular intersecting columns, wherein the protrusions of the complemental roller die are positioned along each row at alternating intersections with the columns intermediate the protrusions of the protrusions of the roller die and each adjacent row having the protrusions offset by one column;
• mounting the roller die rotatably adjacent the complemental roller die and spaced to receive the piece of sheet steel therebetween;
• and
• passing the piece of sheet steel between the rotating roller die and the complemental roller die forming indentations in the pattern of the roller die protrusions on the first side, and forming indentations in the pattern of the complemental roller die protrusions on the second side.