A.
All materials must be of the best quality, free from defects, and all work must be executed in a thoroughly workmanlike manner.
B.
All cast-iron pipes and fittings must be uncoated, sound, cylindrical and smooth, free from cracks, sand holes and other defects, and of uniform thickness, and of the grade known to commerce as "extra heavy"; also must conform to the American Society for Testing Materials "Standard Specifications for Extra-Heavy Cast-Iron Soil Pipe and Fittings" (serial designation A74-18).