Instrumentation Tubing
Overview:
Penflex manufactures unique tubing that is relied on in numerous industries. The tubing is produced by the helical coiling of a cold-rolled 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 InterLok, and is often abbreviated as SL and FI.
Technical Data: SquareLok Style (SL) (made in 304 alloy)

SquareLok 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.
| Size |
Inside Diameter |
Outside Diameter |
Coiling Diameter |
Weight |
Breaking Load Min |
Penflex Part Number |
1/16" 1.6mm |
0.071" 1.8mm |
0.118" 3.0mm |
1.80" 46mm |
0.008lb/ft 0.012kg/m |
45 lbs 20kgs |
SL-SS-001 3280ft/reel |
1/8" 3.5mm |
0.140" 3.5mm |
0.200" 5.1mm |
1.50" 38mm |
0.017lb/ft 0.026kg/m |
60lbs. 27kgs |
SL-SS-002 750ft/reel |
5/32" 4mm |
0.156" 4.0mm |
0.235" 6.0mm |
1.80" 46mm |
0.030 lb/ft 0.045 Kg/m |
145 lbs. 66 Kg |
SL-SS-0025 2200ft/reel |
3/16" 5mm |
0.188" 4.8mm |
0.266" 6.8mm |
1.80" 46mm |
0.033lb/ft 0.049 Kg/m |
150 lbs. 68 Kg |
SL-SS-003 1500ft/reel |
7/32" 5.5mm |
0.218" 5.6mm |
0.303" 7.7mm |
1.80" 46mm |
0.040 lb/ft 0.059 Kg/m |
155 lbs. 70 Kg |
SL-SS-0035 1200ft/reel |
1/4" 6mm |
0.250" 6.4mm |
0.329" 8.4mm |
2.0" 51mm |
0.041 lb/ft 0.061 Kg/m |
190 lbs. 86 Kg |
SL-SS-004 1000ft/reel |
9/32" 7mm |
0.282" 7.2mm |
0.375" 9.5mm |
2.0" 51mm |
0.048 lb/ft 0.072 Kg/m |
200 lbs. 91 Kg |
SL-SS-0045 900ft/reel |
5/16" 8mm |
0.313" 8.0mm |
0.410" 10.9mm |
2.0" 51mm |
0.055 lb/ft 0.082 Kg/m |
200 lbs. 91 Kg |
SL-SS-005 700ft/reel |
3/8" 9.5mm |
0.375" 9.5mm |
0.500" 12.7mm |
2.0" 51mm |
0.088 lb/ft 0.131 Kg/m |
225 lbs. 102 Kg |
SL-SS-006 500ft/reel |
1/2" 12.7mm |
0.500" 12.7mm |
0.625" 15.9mm |
2.5" 64mm |
0.106 lb/ft 0.157 Kg/m |
250 lbs. 113 Kg |
SL-SS-008 300ft/reel |
OD tolerance is +/- 0.008 inches ID tolerance is +/- 0.015 inches (.4mm)
Fully InterLok Style (FI) (made in 304 alloy)

InterLok metal strip and the edges of the strip are completely interlocked with each other. This offers increased crush protection, and higher axial strength.
| Size |
Inside Diameter |
Outside Diameter |
Coiling Diameter |
Weight |
Breaking Load Min |
Penflex Part Number |
3/16" 5mm |
0.188" 4.8mm |
0.266" 6.8mm |
2.0" 51mm |
0.041 lb/ft 0.060 Kg/m |
190 lbs. 86 Kg |
FI-SS-003 1500ft/reel |
7/32" 5.5mm |
0.218" 5.5mm |
0.303" 7.7mm |
2.0" 51mm |
0.045 lb/ft 0.067 Kg/m |
200 lbs. 91 Kg |
FI-SS-0035 1200ft/reel |
1/4" 6mm |
0.250" 6.4mm |
0.329" 8.4mm |
2.0" 51mm |
0.046 lb/ft 0.068 Kg/m |
250 lbs. 113 Kg |
FI-SS-004 1000ft/reel |
OD tolerance is +/- 0.008 inches ID tolerance is +/- 0.015 inches (.4mm)