Section 163.003-11 - Materials(a)Suspension members. Each suspension member must be mildew-resistant manila rope or a dacron polyester rope with a polypropylene core of a color that contrasts with the dacron. Each suspension member must have a breaking strength of not less than 24 kN (5,400 lb.) and a nominal circumference of not less than 60 mm (21/4 in.).(b)Wooden parts. Each wooden part of a pilot ladder must be hardwood that is free from knots and any other defects affecting its strength or durability.(c)Wood preservative. After each wooden part is formed and finished, it must be treated with water-repellant wood preservative that is properly applied.(d)Molded steps. Each step made of molded construction must be rubber or resilient plastic.(e)Metal parts. Each metal fastener must be made of a corrosion resistant metal. Each other metal part must be made of corrosion-resistant metal or of steel galvanized by the hot dip process after the part is formed.(f)Plastics. Each plastic material must be of a type that retains at least 30 percent of its original tensile strength and at least 80 percent of its original impact strength when subjected to the one year outdoor weathering test described in ASTM D 1435.