Welded and Drawn Production Process

Welded and Drawn Production Process

1. Flat strip stock is progressively rolled in mill into a tubular shape.

2. The rolled tube enters a Tungsten Inert Gas (TIG) welding chamber where the tube seam is welded to form a tube. No filler metals are introduced. Atmosphere is tightly controlled for superior cleanliness and no surface oxidation.

3. The tube exits the welding chamber and is collected in coil form at the end of the welding line.

4. Welded coils are transferred to drawing equipment, where coils are drawn through dies and floating plugs to size and work harden tubing and improve surface finishes. Drawing oils are easily removed with conventional surfactants when processing is complete, and these oils are non hazardous per GHS standards. No Teflon® or CFC’s are used.

5. Heat treatments between drawing processes (or after all draws are completed) are applied to soften or harden tubing depending on the alloy and size being produced.

6. Coils of tubing at their final size proceed to straightening, if required, to transform tube into straight lengths.

T.I.G. Welded and Drawn Compared to Laser Welded

Over the decades, experience has readily demonstrated that a more forgiving weld zone and no filler metals produce an optimum fabrication grade material.  Competing processes such as laser welding have several disadvantages when compared to TIG welding. The parameters of the laser weld process require extremely precise strip stock and very tight manufacturing constraints, deviations from which can result in the insufficient weld and subsequent weak points in the tube. One micro-defect at strip edge could potentially translate into a defective tube. By comparison, TIG welding is a more generous manufacturing process, allowing a slight imperfection in raw material to join equally well in the weld zone. Manufacturers of laser-welded tubing often perform the welding very close to final sizing. This may seem like an economical advantage, but without adequate cold work from drawing over a floating plug, some undesirable results can arise: a) total homogenization of the weld zone into the base metal may not be achieved, b) a relatively rough I.D. surface can lead to cleanliness problems, and c) uniform hardness and exacting tolerances are not possible.

Concentricity of welded tubing for hypodermic needles is far superior to seamless. An as-welded laser tube (without plug drawing) will generally have worse concentricity compared to a TIG welded and drawn product because the weld seam sags slightly into the ID of the tube even if only by ten-thousandths of an inch. When applications demand fine finishes, such as laboratory sampling and blood analyzers, Manners can produce premium ID finishes using double and even triple plug draws.

Services

Shenzhen Manners Technology Co.,Ltd is the supplier of some of the world’s famous international companies like Blum Novotest, Komet, Geneva Lab, BTL, etc... We specialize in telescoping parts, needle manufacturing, multi-axis CNC machining, Die casting mold, plastic injection mold, stamping mold, Swiss-type turning, laser cut tubing, tube processing, laser welding and automated assemblies for the medical, endoscopic, arthroscopic, orthopedic, firearms, defense, automotive, and specialty industrial markets.