CYLINDER HEAD ASSEMBLY 5N8501 - Caterpillar

Illustration 1 g00911924Note: For torques for plugs, refer to Specifications, "Plugs".Note: Straight Thread O-Ring fittings for medium pressure usage will have shorter threaded ends than high-pressure fittings. The torque value for medium pressure Straight Thread O-Ring fittings will be lower than the torque values that are required for Straight Thread O-Ring fittings for high-pressure fittings.
Table 1
Ferrous Straight Thread O-Ring Fitting
Torques for Mating with Ferrous Materials
Medium Pressure use Fittings
Nominal Outer Diameter of the Tube Thread Size
Inch Standard Torque
3.18 mm (0.125 inch) 5/16 - 24 10 2 N m (89 18 lb in)
4.76 mm (0.188 inch) 3/8 - 24 13 2 N m (115 18 lb in)
6.35 mm (0.250 inch) 7/16 - 20 30 5 N m (266 44 lb in)
7.94 mm (0.312 inch) 1/2 - 20 30 5 N m (266 44 lb in)
9.52 mm (0.375 inch) 9/16 - 18 40 6 N m (30 4 lb ft)
12.70 mm (0.500 inch) 3/4 - 16 80 12 N m (59 9 lb ft)
15.88 mm (0.625 inch) 7/8 - 14 110 17 N m (81 13 lb ft)
19.05 mm (0.750 inch) 1 1/16 - 12 130 20 N m (96 15 lb ft)
22.22 mm (0.875 inch) 1 3/16 - 12 200 30 N m (148 22 lb ft)
25.40 mm (1.000 inch) 1 5/16 - 12 180 27 N m (133 20 lb ft)
31.75 mm (1.250 inch) 1 5/8 - 12 300 45 N m (221 33 lb ft)
38.10 mm (1.500 inch) 1 7/8 - 12 350 53 N m (258 39 lb ft)
50.80 mm (2.000 inch) 2 1/2 - 12 420 63 N m (310 46 lb ft) Note: Use 50 percent of the torque values from Table 1 when the fitting or the port material is nonferrous.Note: Straight Thread O-Ring fittings for high-pressure usage will have longer threaded ends than medium pressure fittings. The torque value for high-pressure Straight Thread O-Ring fittings will be higher than the torque values that are required for Straight Thread O-Ring fittings for medium pressure fittings.
Table 2
Ferrous Straight Thread O-Ring Fittings
Torques for Mating with Ferrous Materials
High Pressure use Fittings
Nominal Outer Diameter of the Tube Thread Size
Inch Standard Torque
4.76 mm (0.188 inch) 3/8 - 24 20 3 N m (177 27 lb in)
6.35 mm (0.250 inch) 7/16 - 20 30 5 N m (266 44 lb in)
7.94 mm (0.312 inch) 1/2 - 20 45 7 N m (33 5 lb ft)
9.52 mm (0.375 inch) 9/16 - 18 55 8 N m (41 6 lb ft)
12.7 mm (0.500 inch) 3/4 - 16 100 15 N m (74 11 lb ft)
15.88 mm (0.625 inch) 7/8 - 14 140 21 N m (103 15 lb ft)
19.05 mm (0.750 inch) 1 1/16 - 12