Mfrs. of Lockseam, Splitseam, Open/Slotted Seam Tubing. All metals: Prefinished/Plain. Round, Square, Rectangular Special Shape. Lockseam Thicknesses .012-.027 typical; .060” thick is Max. Other .125 thick max, Inline holes, swaging + more. Diameter or height .100”- 4”OD. Tube Styles Not Made: Welded Seam, DOM, Seamless, Drawn & Extruded.