# Welded steel frames teardown: process, India > How welded steel frames are made: tube cutting, CNC bending, jig welding, e-coat and powder, and the checks that matter, with India clusters for each step. Source: https://sourcesquid.co/teardowns/welded-frames/ Example teardown · Welded frames # Welded frames: cycle and light-vehicle steel weldments. A welded frame is tubes, plates, bosses and brackets held in a jig, joined by MAG or TIG welds, then pretreated, coated and checked. This example teardown covers four production weldments, a steering tube, a 20-inch fork, a tow-bar frame and an anti-tip frame, drawn from their 3D models. [Get a free teardown of your product](https://sourcesquid.co/start/?from=teardown-welded-frames) Explore the drawing 4 weldments, 18 parts and processes 6 India clusters in play ISO 5817 weld quality levels Every part has a process ## A welded frame is a supply chain held in a jig. Four steel weldments from cycle and light-vehicle products: a steering tube, a 20-inch fork, a tow-bar frame and an anti-tip frame. Tap a part to see its material, its process chain and the India clusters that weld it. Example teardowns Explode60% Example teardown of four production weldments, drawn from their 3D models. The client, part numbers and exact dimensions are withheld; sizes are rounded. In this teardown ## How it is made, and where 1. What the weldments are made of 2. The process chain 3. Where India is strongest 4. What drives the cost 5. What we inspect **Your product, torn down in 48 hours.** Send a sample, photos, a bill of materials or drawings. We return the process chain, the best clusters and an inspection plan. Free. [Start your teardown](https://sourcesquid.co/start/?from=teardown-welded-frames) 01 ## What the weldments are made of Carbon steel precision tube (E235 to EN 10305) for the bent frames, chromoly (SCM435) for the fork blades and steerer, and stainless 304 for the steering tube, its machined bush and its laser-cut plate. The brackets, dropouts, lock plates and mounting plates are S235, S355 or cold-rolled DC01 sheet and plate, fibre-laser cut and press-brake formed. Bosses and bushes are turned from bar, with threads and bearing seats to tight tolerances such as h6. 02 ## The process chain Tube laser cutting, CNC bending and coping come first, alongside laser cutting and forming of the plates and turning of the bosses. Every part is located in a welding jig, tacked and then welded: MAG (process 135) fillets on carbon steel, TIG (141 and 142) on stainless. A weld sequence that balances heat limits distortion, and straightening or post-weld reaming brings seats and bores back into tolerance. Finishing follows: degreasing and zinc phosphating, then cathodic e-coat (KTL) and powder where specified, with threads, seats and paint-free zones masked. Stainless parts are pickled and passivated to remove heat tint instead. 03 ## Where India is strongest Ludhiana has the deepest base of tube bending and MAG welding, grown on bicycles and their parts. Pune–Chakan and Chennai–Hosur add robotic welding cells, automotive-grade KTL lines and machining for bosses. Faridabad adds sheet-metal fabrication, and Rajkot builds the welding jigs and check fixtures that everything else depends on. 04 ## What drives the cost Tube grade and wall, the number of bends and bend tools, arc-on time per part, manual versus robotic welding, and straightening labour. Jig and fixture cost is spread over volume. Coating route matters too: phosphate and KTL, powder, or both, plus masking time. Distortion scrap and rework are the hidden cost that good jigs and weld sequences remove. 05 ## What we inspect The jig first: every locator measured against the drawing on a CMM before the first weld. Then weld penetration on a cut-and-etch macro of the first article, visual weld quality to ISO 5817 (size, undercut, porosity and spatter), fixture-to-drawing alignment, head-tube parallelism and dropout alignment. On the coating: dry-film thickness, cross-hatch adhesion to ISO 2409 and salt-spray hours to ISO 9227 on test panels. Example teardown for illustration. Standards named here are the ones we usually check against; your drawing and target market set the exact scope. Weldments questions ## Straight answers. Anything else, ask us directly. A principal replies, not a bot. [anirudh@sourcesquid.co](mailto:anirudh@sourcesquid.co) ### Where in India are welded steel frames made? Ludhiana leads in tube bending and MAG welding for cycle and mobility frames. Pune–Chakan and Chennai–Hosur add robotic welding and automotive-grade e-coat lines, Faridabad adds sheet-metal fabrication, and Rajkot builds welding jigs and fixtures. ### What is ISO 5817? ISO 5817 sets quality levels (B, C and D) for imperfections in fusion welds in steel, such as undercut, porosity and excess spatter. Your drawing or specification should name the level; we inspect welds against it. ### Why cut and etch a weld? A visual check only shows the surface. Sectioning a first-article weld and etching it shows penetration and fusion into both parts, which is what gives a joint its strength. ### KTL e-coat or powder coat? E-coat (KTL) reaches inside tubes and gives strong corrosion protection at a thin film; powder gives a thicker, decorative top coat. Many frames use zinc phosphate and KTL, with powder on top where appearance matters. ### Can you work from my 3D files and drawings? Yes. We read STEP files and drawings under NDA, check weld symbols, tolerances and finishes, and return a process chain, a cluster shortlist and an inspection plan. The first teardown is free and takes 48 hours. ## More example teardowns. 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