Section 179.200-10 - Welding(a) All joints shall be fusion-welded in compliance with the requirements of AAR Specifications for Tank Cars, appendix W (IBR, see §171.7 of this subchapter). Welding procedures, welders and fabricators shall be approved.(b) Welding is not permitted on or to ductile iron or malleable iron fittings.29 FR 18995, 12/29/1964. Redesignated at 32 FR 5606, 4/5/1967, and amended by Amdt. 179-10, 36 FR 21350, 11/6/1971; 68 FR 75761, 12/31/2003