STL series adjustable student chair, height group 4-6 on slides

The lower part of the frame is made of oval thin-walled electric-welded tube. The slides are made of 45*25mm section, the thickness of the pipe wall is 1.5mm. The ends of the slides are closed with a support plug. The cap is fixed to the pipe with a rivet. Overall length of the plug is 110mm. The thickness of the support part of the plug is 6,5 mm. The support parts made of an oval thin-walled electrically welded pipe of 45*25mm cross-section, pipe wall thickness 1.5mm, are welded perpendicularly to the slides. The upper part of the adjusting mechanism is made of oval thin-walled electric-welded pipe with cross-section: 50*30mm, pipe wall thickness 1,5 mm. The upper part of the chair frame is made of a flat-oval tube with cross-section size 30x15mm, wall thickness 1,5 mm. The horizontal lintel is made of round thin-walled electrically welded pipe with a diameter of 18 mm, the wall thickness of the pipe is 1,5 mm.