Tech Tube's sizes range from 0.030" to 1.250" outside diameter (OD) and 0.003" to 0.280" wall. The table (below) provides standard sizes and tolerances. Please consult the Sales Department for closer or different tolerances are required.
| Manufacturing Standards: | |||||||||
| Tube OD | Tube ID | Tube Wall | StraightnessA | LengthA | |||||
| Size | ToleranceA,B | Size | ToleranceA,B | Size | ToleranceA,B | Random | Exact | ||
| Up to .100" | +/- .001 | Up to .100" | +/- .001 | Up to .005" | +/- .0003 | .010" per 1' length | +/- 3.5' | +/- .010" | |
| .0051" to .010" | +/- .0005 | ||||||||
| .0101" to .020" | +/- .001 | ||||||||
| .101" to .250" | +/- .002 | .101" to .250" | +/- .002 | Up to .005" | +/- .0005 | .010" per 1' length | +/- 3.5' | +/- .010" | |
| .0051" to .010" | +/- .0008 | ||||||||
| .0101" to .020" | +/- .001 | ||||||||
| .0201" to .050" | +/- 10% | ||||||||
| .251" to .500" | +/- .003 | .251" to .500" | +/- .003 | Up to .005" | +/- .0005 | .010" per 1' length | +/- 3.5' | +/- .010" | |
| .0051" to .010" | +/- .0008 | ||||||||
| .0101" to .020" | +/- .001 | ||||||||
| .0201" to .050" | +/- 10% | ||||||||
| Over .0501" | +/- 10% | ||||||||
| .501" to .750" | +/- .004 | .501" to .750" | +/- .004 | .0101 to .020" | +/- 10% | .010" per 1' length | +/- 3.5' | +/- .010" | |
| .0201" to .050" | +/- 10% | ||||||||
| Over .0501" | +/- 10% | ||||||||
| .751" to 1.25" | +/- .005 | .751" to 1.25" | +/- .005 | .0101" to .020" | +/- 10% | .010" per 1' length | +/- 3.5' | +/- .010" | |
| .0201" to .050" | +/- 10% | ||||||||
| Over .0501" | +/- 10% | ||||||||
| A: Custom tolerances are available upon request | |||||||||
| B: SPC data (Cp, Cpk, s, etc.) and # of samples per lot can be tested/reported upon customer request. | |||||||||
| * Condition Tempers: Standard tempers are annealed, 1/4, 1/2, and full hard. Custom tempers are available upon request. | |||||||||
| ** % Concentricity can be calculated by request using the following formula: 2x ((Max wall -Min wall)(Max wall +Min wall))x 100 | |||||||||
Tolerances
- OD tolerances are measured using micrometers. Laser micrometers are used for thin walls or extra close tolerances. Ovality will be within the OD tolerance for tubes where the wall thickness is at least 3% of the nominal OD.
- ID tolerances require special definition because of the different interpretations. Three methods of inspection are described here:
- Go/No-Go Plug Gauge: The Go Plug will go into the ID of the tube. The No-Go Plug will not start. For Example: For a 0.25" +/-0.004" ID tube, a 0.246" plug will go into the ID of each tube. A 0.250" will not start. Note that a 0.250" plug will not fit into a .250" hole. This is standard method for inspecting tubing and will be used unless otherwise specified at the time of inquiry.
- Go Through/No-Go Through Plug Gauge: The Go Plug will pass freely through the entire length of the tube. The No-Go Plug may start but will not go freely into the ID for the length of the plug.
- ID Micrometer: When size permits, tubes may be measured with an ID micrometer. Results may be different than those measured with Plug gauges. Also ID micrometers may be "three-point" micrometers that will measure average ID or "two-point" which will measure the high and low values.
- Eccentricity: The difference between the center of the circle formed by the tube OD and the center of the circle formed by the tube ID. Commercial tolerance for eccentricity is +/- 10% of the average wall thickness (20% TIR). Closer tolerances can be supplied if required.
- Straightness: Commercial straightness is 0.010" per foot of length; that is, a tube 10 feet long will be straight within 0.100". Closer tolerances can be supplied if required.
- Length Tolerances: Random lengths: +/- 3.5 feet. Cut lengths: up to and including 1 foot +/- 0.010"; over 1 foot +/- 0.125"-0. Closer tolerances can be supplied if required.
- Shape Tube Tolerances: major axis +/- 0.005". minor axis +/- 0.003". Closer tolerances can be supplied if required.
- Surface Roughness: Special OD and ID surfaces are available. Contact our Sales Department with specific requirements.
- Tempers: Annealed is standard but 1/4, 1/2, and full hard are also available. Customer specified harnesses and tempers are also available.