TongFengflex manufactures unique tubing that is relied on in numerous industries. The tubing is produced by helical coiling of metal strip onto a spindle, with the helical coils being linked with each other by means of a special type of strip profile. Basic materials for the strip are stainless steel. However, other metals are also available.
Applications: Instrumentation tubing is used by manufacturers of various industries, such as Process & Control Instrumentation, Measuring & Controlling Devices, Analytical Instruments, Medical Instruments and many others with specific applications including temperature measuring, wiring conduit or armor cable and protective casing.
Instrumentation tubing is made in two configurations, or constructions, commonly called SquareLok and InterLock, and is often abbreviated as TF-D and TF-S.
Technical Data:
SquareLok Style (TF-D)SquareLock tubing is produced from a continuous metal strip, and is held in position by locking one leg of one profile over the leg of the adjacent profile.
TYPE  ID OD Tolerance +/-
 Weight
] Bending radius  Load strength  Tensile strength
TF-D0406 4 6 0.1 0.034 15 800 320
TF-D0507 5 7 0.1 0.039 17 835 340
TF-D0608 6 8 0.1 0.044 19 875 360
TF-D0709 7 9 0.1 0.049 20 930 380
TF-D0810 8 10 0.1 0.056 22 975 400
TF-D0911 9 11 0.1 0.063 25 1020 450
TF-D1013 10 13 0.1 0.100 30 1060 500
TF-D1114 11 14 0.1 0.110 31 1095 550
TF-D1215 12 15 0.1 0.120 32 1140 600
TF-D1316 13 16 01 0.130 33 1175 650
TF-D1417 14 17 0.1 0.140 35 1215 700
TF-D1518 15 18 0.1 0.150 37 1250 720
TF-D1619 16 19 0.1 0.160 40 1290 760
TF-D1720 17 20 0.1 0.170 45 1330 800
TF-D1821 18 21 0.1 0.180 42 1470 890
TF-D1923 19 23 0.2 0.212 40 1510 840
TF-D2024 20 24 0.2 0.223 42 1545 890
TF-D2125 21 25 0.2 0.235 45 1580 920
Fully InterLock Style (TF-S) InterLock metal strip and the edges of the strip are completely interlocked with each other.  This offers increased crush protection, and higher axial strength..
TYPE  ID OD Tolerance +/- Weight
 Bending radius  Load strength  Tensile strength
TF-S0406 4 6 0.1 0.053 25 900 200
TF-S4267 4.2 6.7 0.1 0.066 28 955 285
TF-S5378 5.3 7.8 0.1 0.079 32 1000 395
TF-S5580 5.5 8 0.1 0.082 35 1050 400
TF-S5984 5.9 8.4 0.1 0.086 38 1185 450
TF-S6590 6.5 9 0.1 0.093 40 1125 500
TF-S8011 8 11 0.1 0.141 45 1275 700
TF-S9012 9 12 0.1 0.159 50 1340 800
TF-S1013 10 13 0.1 0.177 55 1415 900
TF-S1114 11 14 0.1 0.195 65 1480 1000
TF-S1215 12 15 0.1 0.213 70 1550 1100
TF-S1316 13 16 0.1 0.230 75 1620 1200
TF-S1417 14 17 0.1 0.248 80 1690 1300
TF-S1518 15 18 0.1 0.265 82 1765 1400