Start from thickness, not brand hype
MIG welders are sold by maximum output, process modes, and duty cycle together. A “200 A” badge does not mean every joint at 200 A is comfortable — you still need enough headroom above your starting amps. This site maps mild steel thickness in inches to three verified VEVOR US MIG classes using the common Miller starting estimate.
The Miller starting rule (flat mild steel)
Training materials and field charts often cite roughly 1 amp of welding current per 0.001 in of mild steel thickness for flat-position GMAW starting points. Example: 0.1875 in (3/16 in) → about 188 A starting amps, which rounds up to the 200 A class on this ladder. Vertical-up, overhead, out-of-position, stainless, and aluminum need different procedures — do not copy the flat mild steel number blindly.
MIG amp class ladder on this site
MigAmps maps thickness to three verified VEVOR US MIG classes: 130 A (flux-core inverter example), 200 A (5-in-1 synergic example), and 250 A (3-in-1 gas/gasless example). The smallest class whose published ceiling covers your starting amps is shown. Starting amps above 250 A return NO_MATCH instead of recommending an undersized consumer inverter.
Typical garage thickness reference points
Auto body patch panels and light brackets often sit near 1/16–1/8 in (0.062–0.125 in). Trailer hitch plates and heavier brackets commonly land near 3/16–1/4 in (0.1875–0.25 in). Always measure your actual workpiece — gauge numbers vary by supplier. Sources reviewed for this methodology include Miller GMAW starting guidance and VEVOR US MIG welder listings checked 2026-09-10.
Limits and honesty rules
This screen does not account for wire diameter tables, spray transfer, pulse programs, preheat, multi-pass bevels, or industrial synergic lines above 250 A. Affiliate tracking is pending. Product links are ordinary VEVOR merchant URLs; availability can change. A matched amp class is not a welding procedure specification — verify WPS, gas, and inspection requirements for your job.