These macromolecules are polar [polar: having different ends] because they are formed by head to tail condensation of polar monomers. Let's look at the three major classes of macromolecules to see how this works, and let's begin with carbohydrates.
Bostwick Steel Lath Company advertisement for steel truss loop type metal lath in 1920. A lath or slat is a thin, narrow strip of straight-grained wood used under roof shingles or tiles, on lath and plaster walls and ceilings to hold plaster, and in lattice and trellis work.
Cutting thick metal is a little different than cutting sheet metal. Thick metal means slower cutting, wider cut or kerf, more slag remaining (the leftover molten metal on the edge of the cut), and longer pierce time. If you are piercing the metal, the 45Â° angle is vital.