This specification covers double submerged-arc welded, black, plain end steel pipes for use in the conveyance of fluids under pressure. The pipes shall be capable of being welded in the field. Skelp widths for helical seam pipe shall be neither less than 0.8 nor more than 3.0 times the pipe's specified outside diameter. Skelp end welds shall not be permitted in finished pipe, except for helical seam pipe having its skelp end welds manufactured by double submerged-arc welding. For such pipes, skelp ends shall have been properly prepared for welding. The specimens shall undergo the following tests: tension test, guided bend test, Charpy V-notch test, and hydrostatic test. After hydrostatic test, nondestructive examinations by ultrasonic inspection shall be done.