Table  6-1.—Corrosion-Resistant  Steel  Tubing Specification Tubing Material Type Condition General Usage and Applications MIL-T-7081 6061 A1 Specification  covers  annealed  and  three  heat treated tempers used mostly in 0-annealed and T-6. Has good workability. The 6061-T6 is used in  hydraulic/pneumatic  3000  psi  systems. MIL-T-8506 304 Annealed Low-pressure  applications  such  as  fuel  lines. 18-8 Unsatisfactory  for  high-pressure  hydraulic  lines. Corrosion-Resistant Has  high  degree  of  resistance  to  corrosion. Steel (CRES) MIL-T-8504 304 Annealed Unsatisfactory  for  welding,  brazing  or  exposure 18-8 to temperatures higher than 800°F. Used in CRES high-pressure  hydraulic/pneumatic  systems. MIL-T-8606 304L Annealed Hydraulic/mechanical applications. Has high 18-8 (low carbon) resistance to corrosion and high temperatures up CRES 321 to  1500°F.  Suitable  for  applications  requiring 347 welding/brazing. Type II intended for high-pressure  hydraulic  applications,  using brazed  sleeve  joints. MIL-T-6845 304 1/8H Used  in  high-pressure  hydraulic/pneumatic 18-8 systems. Unsuitable for welding/brazing CRES applications  or  exposure  to  temperatures  above 800°F. MIL-T-8973 304L 1/8H Used  in  high-pressure  hydraulic/pneumatic 18-8 (low carbon) systems  assembled  with  brazed  sleeve  joints. CRES 316L Suitable  for  use  in  moderately  corrosive  or (low carbon) oxidizing  environments,  temperatures  to  1200°F. 321 Weldable. 347 MIL-T-5695 304 1/4H Used for aircraft structural parts or similar 18-8 1/2H applications not requiring sharp bends or flaring. CRES Unsatisfactory for welding other than resistance weld. MIL-T-8808 321 Annealed Aircraft hydraulic quality, used in high-pressure 18-8 347 hydraulic/pneumatic  systems.  Most  often  used  in CRES these  systems  requiring  brazing/welding. 6-2