Capabilities

General Information

Standard and specialty tubing is available in a variety of alloys to meet your specific applications. We offer stainless steel, high temperature, corrosion resistant, and nickel alloys. Most alloys are available as seamless or welded and drawn tubing.

Size Limits and Tolerances

Tube Methods’ sizes range from 0.030” to 1.50” outside diameter (OD) and 0.002” to 0.280” wall. Inner diameters can be sized down to 0.008". Metric sizes are available. Please consult our Sales department if closer or different sizes are required.

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 different interpretations. Three methods of inspection are described below.

Commonly Requested Tolerances*

Tube OD (inches) Outside Diameter Inside Diameter Wall Thickness
Up to and including 0.2505" ±0.002" ±0.002" ±10%
0.251" through 0.5005" ±0.003" ±0.003" ±10%
0.501" through 0.7505" ±0.004" ±0.004" ±10%
0.751" through 1.250" ±0.005" ±0.005" ±10%

*Custom tolerances are available upon request.

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 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 Tolerance:

  • Random Lengths: ±3.5 feet
  • Cut Lengths: Up to and including 2 feet: ±0.010"; over 2 feet tolerances: ±0.125"
  • 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 1/8 hard, 1/2 hard, full hard, and heat treated are also available.
  • Customer specified hardnesses and tempers are also available.

Standard Shapes:

  • Round
  • Flat Oval
  • Elliptical
  • Rectangular
  • Square
  • Custom

Definitions

Unless otherwise requested, Pin Class Z is used throughout all processes.

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 0.250” +0/-0.004” ID tube, a 0.246” plug will go into the ID of each tube. A 0.250” plug will not start. Note that a 0.250” plug will not fit into a 0.250” hole. This is the standard method for inspecting tubing and will be used unless otherwise specified at time of inquiry.

Go Thru/No-Go Thru Plug Gauge: The Go Thru Plug will pass freely through the entire length of the tube. The No-Go Thru 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. Note: ID micrometers may be “three-point” micrometers, which will measure average ID, or “two-point” micrometers, which will measure the high and low values.

ID Air Gauge: Air gauges are used in applications where highly precise measurements are required. A hardened steel probe is inserted into the ID of a tube, where air is pushed through the body of the probe and out small outlet holes. The tube creates a backpressure into the probe, where measurements are recorded. Since the probe does not need to touch the tube to record a measurement, all possible contaminents can be blown away, resulting in a highly precise recording.