Systems and methods for threading a hot coil on a mill

A method of threading a metal substrate on a hot or warm rolling mill comprising:

• receiving a coil of the metal substrate at an elevated temperature, wherein the elevated temperature is greater than 450° C., and wherein the metal is aluminum or an aluminum alloy;
• uncoiling the metal substrate from the coil while the coil is at the elevated temperature;
• and
• guiding the metal substrate to a work stand of the hot or warm rolling mill with a threading carriage and such that the metal substrate is received at the work stand at the elevated temperature,
• wherein the threading carriage comprises at least one of:
• a pair of gripping rolls, wherein the method comprises gripping the metal substrate with the threading carriage by directing the metal substrate between the pair of gripping rolls and gripping the metal substrate with the gripping rolls at a position that is offset from a leading edge of the metal substrate, wherein the method further comprises adding stiffness to the metal substrate by adding a diameter profile along a length of the gripping rolls such that the metal substrate comprises at least one non-planar lateral curvature across a width of the metal substrate while guiding the metal substrate to the work stand;
• or
• a gripping wedge, wherein the method comprises gripping the metal substrate with the threading carriage by directing the metal substrate through the gripping wedge and closing the gripping wedge on the metal substrate at a position that is offset from a leading edge of the metal substrate to grip the metal substrate, and wherein the method further comprises adding stiffness to the metal substrate by closing the gripping wedge and crimping the metal substrate with the gripping wedge such that the metal substrate comprises at least one non-planar lateral curvature across the width of the metal substrate.