Tubing Manufacturing Process

Our production process combines proven methods and new technologies to consistently produce TIG welded and mandrel drawn tubing of very high quality at economical costs. American Tube uses the Tungsten Inert Gas (T.I.G.) welded and plug (or mandrel) drawn method. This multi-step process can be broken down into 4 major segments:

• Stainless steel strip is roll formed and welded in an inert gas atmosphere. No filler materials are used. 
• The tubing is drawn through a die and floating plug or mandrel for initial wall sizing. 
• Subsequent draws (with or without floating plugs) occur for final sizing, added strength and ID / surface finish requirements.
• Secondary processes such as straightening or annealing are completed.

The welding is completed in an inert atmosphere (proprietary formula), which minimizes oxidization and any potential added impurities. One of the T.I.G. method's advantages is its forgiving weld zone which allows strip with minor edge imperfections to join evenly during the welding process. Alternate methods with smaller weld zones can be subject to weaknesses in the seam from production setup errors, slight manufacturing process variations or raw strip with manufacturing deviations. Since our method uses no filler material, the chemistry of the selected alloy is consistent throughout the tube. 

Our stainless steel / nickel tubing drawing process relies on our set of hundreds of dies and plugs to size the tube and occurs without CFC's or other environmentally harmful products. The drawing process also functions to homogenize the weld zone into the base metal and improve the cosmetic appearance of the tube. The drawing compound is a breakthrough, trade protected oil formula that cleans easily. Teflon® is never used. The concentricity of ATT's welded and drawn tubing is greater than possible from many seamless processes. For some orders, we use multiple draws and intermediate anneals to further control such variables as wall size, tensile strength, and finishes. In fact, our proprietary process allows us to produce smoother bore tubing compared to competing commercial mills. Our full hard temper tubing typically has a minimum tensile strength of 150 KPSI.

Full hard temper (medical grade small diameter tubing) is standard and preferred by many of our customers. Those who need softer tempers can select from intermediate tempers or an annealed condition. Specific needs can be discussed with our staff regarding specifications or what options are the most economical considering your application. 

We ship either coils or straight lengths up to 20' long from our Denver, CO. factory. For fabricated tubing parts, we can refer you to one of our partners for complete assistance. Full material certifications are provided with every order.