The buying framework
For thin stainless work, prioritize controllability, fit and workflow before jumping to maximum power. For thicker recurring work, 1200W-class headroom can materially affect the shortlist.
Published thickness examples
xTool lists 4 mm stainless/carbon steel for MetalFab 800W and 5 mm for 1200W. GWEIKE lists an overall 0.2–4 mm and 0.2–5 mm processing range for its 800W and 1200W variants.
Finish and distortion
Localized heat input is part of the appeal of laser welding for sheet work, but final quality still depends on settings, joint fit-up, operator technique and material condition.
Safety note: Handheld fiber laser welders are high-power Class 4 laser systems. Use appropriate engineering controls, laser-rated PPE, training and a controlled work area. Always follow the exact manufacturer manual.