Comparison : Item # 1317-12-001, 1/8" Tube O.D. (5/16-28 Thread) Inverted Flare Zinc Chromate Steel Nut
Item # 1317-12-002, 3/16" Tube O.D. (3/8-24 Thread) Inverted Flare Zinc Chromate Steel Nut
Item # 1317-12-003, 1/4" Tube O.D. (7/16-24 Thread) Inverted Flare Zinc Chromate Steel Nut
Item # 1317-12-004, 5/16" Tube O.D. (1/2-20 Thread) Inverted Flare Zinc Chromate Steel Nut
Item # 1317-12-005, 3/8" Tube O.D. (5/8-18 Thread) Inverted Flare Zinc Chromate Steel Nut