Service Information Guide (All models) 14A-19 Note The tightening torque of the tapered thread for products other than connectors and brass products is only applied when the opposite side is not made of aluminum. Note For the elbow-type connector, tighten it with the minimum torque shown above and then tighten it further until the angle matches. Apply Loctite 575 to the threaded portion and tighten. Completely dry then let air in after tightening. Do not use seal tape, etc.
Pipe diameter Tightening torque for large/medium size vehicles Flare nut width across flat Previous New Tightening torque of the flare nut Service standard value ： 4.6 mm { 0.181 in } ： 12.8 to 18.6 N・m { 1.3 to 1.9 kgf・ m / 9 to 14 lb・ft } ： 14 mm { 0.55 in } ： 14 mm { 0.55 in } ： 6.35 mm { 0.25 in } ： 23.5 to 49.0 N・m { 2.4 to 5.0 kgf・ m / 17 to 36 lb・ft } ： 17 mm { 0.67 in } ： 17 mm { 0.67 in } ： 8.0 mm { 0.31 in } ： 23.5 to 49.0 N・m { 2.4 to 5.0 kgf・ m / 17 to 36 lb・ft } ： 19 mm { 0.75 in } ： 17 mm { 0.67 in } ： 10.0 mm { 0.39 in } ： 44.1 to 93.2 N・m { 4.5 to 9.5 kgf・ m / 33 to 69 lb・ft } ： 22 mm { 0.87 in } ： 19 mm { 0.75 in } ： 12.0 mm { 0.47 in } ： 58.8 to 137.3 N・m { 6.0 to 14.0 kgf・ m / 43 to 101 lb・ft } ： 27 mm { 1.06 in } ： 24 mm { 0.94 in } ： 15.0 mm { 0.59 in } ： 78.5 to 156.9 N・m { 8.0 to 16.0 kgf・ m / 58 to 116 lb・ft } ： 30 mm { 1.18 in } ： 30 mm { 1.18 in } Tapered thread for connectors and brass products Screw size PT (R) 1/8 PT (R) 1/4 PT (R) 3/8 PT (R) 1/12 - ： 2.0 to 14.7 N・m { 0.20 to 1.50 kgf・m / 18 to 130 lb・in } ： 4.9 to 15.7 N・m { 0.5 to 1.6 kgf・m / 43 to 139 lb・in } ： 9.8 to 16.7 N・m { 1.0 to 1.7 kgf・m / 87 to 148 lb・in } ： 9.8 to 17.7 N・m { 1.0 to 1.8 kgf・m / 87 to 157 lb・in } Tapered thread for products other than connectors and brass products Screw size PT (R) 1/8 PT (R) 1/4 PT (R) 3/8 PT (R) 1/2 PT (R) 3/4 - ： 5.9 to 11.8 N・m { 0.6 to 1.2 kgf・m / 52 to 104 lb・in } ： 14.7 to 29.4 N・ m { 1.5 to 3.0 kgf・ m / 11 to 22 lb・ft } ： 29.4 to 39.2 N・ m { 3.0 to 4.0 kgf・ m / 22 to 29 lb・ft } ： 29.4 to 58.8 N・ m { 3.0 to 6.0 kgf・ m / 22 to 43 lb・ft } ： 58.8 to 98.0 N・ m { 6.0 to 10.0 kgf・m / 43 to 72 lb・ft }