Skill in formulating plans, patterns, and templates involving straight and curved edges or irregular curves, angles, and planes; in layout and pattern development (including geometric projection and triangulation); in fabricating complex items from a variety of materials such as galvanized or stainless steel, black iron, aluminum, copper sheet, magnesium, honeycomb material, and alloys; in using and maintaining a variety of metal shop tools, equipment, and measuring instruments; and in assembling, fabricating, and repairing sheet metal systems, components, and items. Requires physical effort which includes prolonged standing on production lines; climbing up and down ladders and scaffolds; working in cramped and awkward positions while installing items; and reaching, lifting, and bending while using hand and powered tools in uncomfortable positions for extended periods.