S28E7: Metal Nail Files, Birch Bark Canoes, Cruiser Boat Hardtops, High-Voltage Circuit Breakers

Steel blanks are cut, textured, hardened and finished to produce durable metal nail files. Sheets of birch bark are fitted around a wooden framework and reinforced with ribs to create traditional canoes; composite materials are moulded and finished into hardtops for cruiser boats; and insulated contacts and interruption mechanisms are assembled into high-voltage circuit breakers.