TM  55-1520-240-23-1 1-13 STANDARD  TORQUE  LIMIT APPLICATION (Continued) 1-13 Standard  Torque Limits  in  Inch-Pounds  for Pipe  Thread Fittings Be  careful when  tightening fitting.  Overtightening causes  distortion, cracking, and leaks. THREAD  SIZE WORKING  TORQUE¹ MAXIMUM  TORQUE¹ 1/8-27 100 175 1/4-18 150 300 3/6-18 225 450 TORQUE   WRENCHES 30  to  150  Inch-Pounds 100  to  750  Inch-Pounds ¹Antiseize compound (E75)  shall be used on threads  to  prevent seizing  and to aid  in  sealing.  The compound  shall be applied to the male fitting so  that it does  not contaminate the fluid in the system.  Male  and female  fittings  should be of different materials. Bulkhead Fitting Hole  Diameter,  Washer Thickness,  and Nut  Torque  Limits Be  careful  when  tightening  fittings.  Overtightening  causes  distortion,  cracking,  and  leaks. TUBE  FITTING BULKHEAD HOLE DIA  (INCH) WASHER THICKNESS TORQUE (INCH-POUND) AN924  NUT TUBE SIZE OD  (INCH) THREAD MIN MAX (INCH) MIN MAX -4 1/4 7/16  - 20 .443 .463 .063 85 105 -5 5/16 1/2 -  20 .505 .525 .063 105 125 -6 3/8 9/16  - 16 .568 .588 .063 120 150 -8 1/2 3/4 -  16 .755 .775 .090 240 280 -10 5/8 7/8 -  14 .880 .990 .090 320 380 -12 3/4 1-1/16 -  12 1.068 1.088 .090 500 600 -16 1.0 1-5/16 -  12 1.318 1.338 .090 720 880 -20 1-1/4 1-5/8  - 12 1.630 1.650 .090 960 1200 END  OF  TASK 1-16