This specification covers Zinc Coated (Galvanized) Corrugated Iron or Steel Culverts and Underdrains. Note 1- This specification is a manufacturing and purchase specification only@ and does not include requirements for bedding. Backfill@ or the relationship between earth cover load and culvert sheet thickness of the pipe. However@ experience has shown that the successful performance of this product depends in equal amounts upon the proper selection of the culvert sheet thickness@ type of bedding and backfill@ control manufacture in the plant@ and care in the field construction work. The purchaser of the corrugated iron or steel pipe specified herein is cautioned that he must properly correlate the field requirements with the culvert sheet thickness of the pipe and provide adequate inspection in the manufacturing plant and at the construction site. The purchaser is also cautioned that he must properly correlate the corrosion and abrasion requirements of the field installation with the culvert sheet thickness and/or appropriate coatings of the pipe. And provide for adequate protection where indicated.