Longitudinal Seam (GTAW) Welding Services

Longitudinal Seam Gas Tungsten Arc Welding (GTAW)What is Longitudinal Seam Welding? 

Longitudinal Seam Gas Tungsten Arc Welding (Longitudinal Seam GTAW) is a semi-automated process that produces full penetration welded seams in sheet metal components with the Gas Tungsten Arc Welding (GTAW) method. This process easily enables the joining of two flat plates of material together to form a cylinder. Longitudinal seam welding can be used on smooth plates, sheets, pipes, and tank sections to make cylindrical workpieces.

Gas Tungsten Arc Welding applies a non-consumable tungsten welding rod and intense heat to a base metal to create a weld. The metals in the bond can be melted directly together to create an autogenous weld. The combination of heat, the tungsten power arc, and shielding gases can also be applied to a long list of filler materials, including exotic and unusual alloys.

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Longitudinal Seam Welding Advantages

  • Thickness range of .010” to .188”
  • Diameters 2” to 48” and flat sheet
  • Lengths up to 60” long
  • Post-weld planishing available
  • Clean welds and processing, no sparks or splatter
  • High precision, clean and precise welds free of slag
  • Useful for most common metals
  • Airtight, accurate single-seam and parallel-seam welds for cones, boxes, and flat sheets
  • High welding speed with extreme accuracy
  • Quick turnarounds for large-scale projects with low tensile and fatigue strength

Certified Weld Inspection Services

Additionally, Superior Joining Technologies offers certified weld inspection services compliant with the AWS (American Welding Society) and Non-Destructive Testing (NDT) processes.

Industries Served

Longitudinal seam welding is valued in a large variety of industries.

  • Aviation
  • Aerospace
  • Medical
  • Defense
  • Nuclear
  • Industrial
  • Maritime


Applications within these industries require air-tight, strong seals on the welded longitudinal seam.

  • Roll-formed, flat sheet, strip materials
  • Boiler making
  • Gas cylinders
  • Pressure vessels
  • Heat exchangers
  • Structural pipe


At SJTI, longitudinal seam welding is a useful process for a wide variety of materials including carbon steel, stainless steel, thin steel, thin aluminum, carbon steel, stainless steel, Inconel, and Monel. 

Sheet Rolling


Sheet Rolling

Sheet rolling is a value-added service we offer in conjunction with our Longitudinal Steam GTAW and Circumferential Seam Welding services to fabricate custom pressure vessels as used in aerospace applications. We can handle materials from 0.010" thick stock 60" wide, for diameters from 2.00" to 48."


Value-Added Services

SJTI is offering longitudinal seam welding services in combination with our well-established support services such as Certified Weld Inspection (CWI) services in compliance with the AWS, as well as Non-Destructive Testing (NDT) processes fully NADCAP accredited by PRI—including Penetrant Testing (PT) and Magnetic Testing (MT). Let us provide Longitudinal Seam Welding services for your roll-formed, flat sheet and strip materials, or let us form it for you here. We are ready to serve you with high-level quality and rapid response times.

Superior Joining Technologies, Inc. has the certifications and experience you are looking for in a longitudinal seam welder. Our longitudinal seam welding process is approved by Boeing, GE, Unison, Collins Aerospace, and Safran. We are proud to be a woman-owned company.

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