Metal fabrication welding guide covering layout, fit-up, fixture design, production welding, and quality standards. From one-off projects to production runs, with process selection and joint design for fab shop work.
Metal fabrication is where layout, cutting, forming, and welding come together to build something from raw stock. The welding is only one step in the process, and it’s rarely the hardest part. Getting parts cut accurately, bent to dimension, and fitted tight before welding is what separates professional fabrication from hobby work.
Layout and marking start every job. Accurate measurements transfer from drawings to material using scribes, soapstone, layout fluid, and combination squares. A 1/16-inch error in layout becomes a 1/8-inch gap at assembly. Measure twice, cut once isn’t just a saying in fab work.
Cutting includes shearing, band saw, plasma, oxy-fuel, and abrasive wheel methods. Each has its place. Plasma handles complex profiles and thinner material. Band saws give you straight, square cuts on bar stock and tubing. Oxy-fuel still works best for thick plate in field conditions.
Fit-up and fixturing determine weld quality more than anything else. Root openings, bevel angles, and alignment tolerances need to match the welding procedure specification (WPS) for the joint. Tack welds hold parts in position during full welding, and their placement matters. Tack at the ends first, then fill in the middle to control distortion.
Production welding requires consistency across hundreds or thousands of identical joints. Proper wire feed speed, travel speed, and work angle become muscle memory. Welders working to AWS D1.1 or D1.3 need to stay within qualified parameters on every joint.
Quality control includes visual inspection, dimensional checks, and destructive or non-destructive testing depending on the application. Most fab shops at minimum perform visual inspection per AWS D1.1 criteria: checking for undercut, porosity, incomplete fusion, and correct weld size.
For process settings, see our welding processes section. Return to the welding applications overview for other industry guides.
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