How to Tell If Your Weld Is Good

Learn to spot the difference between a quality weld and one with defects. Visual guide for MIG, TIG, Stick, and Flux-Core welders.

Signs of a Good Weld

✓ GOOD

Consistent Bead Width

The weld bead maintains the same width throughout its length. This indicates steady travel speed and proper technique.

✓ GOOD

Smooth, Even Ripples

TIG welds should have uniform "stacked dimes" appearance. MIG welds should show consistent ripple patterns without gaps or bunching.

✓ GOOD

Clean Tie-Ins at Edges

The weld should blend smoothly into the base metal at the toes (edges) without grooves, overlap, or gaps.

✓ GOOD

Proper Reinforcement Height

The weld should be slightly raised above the base metal (reinforced), but not excessively. Too flat = underfill. Too high = waste and stress.

Common Weld Defects to Watch For

✗ DEFECT

Porosity

Small holes or pits visible on the weld surface. Caused by gas contamination from wind, moisture, or shielding gas issues. Weakens the weld.

✗ DEFECT

Undercut

A groove melted into the base metal along the weld edges. Caused by too much heat or wrong angle. Creates stress concentration points.

✗ DEFECT

Cracks

Any visible crack in the weld or heat-affected zone. Critical defect - automatic failure in inspections.

⚠ MINOR

Excessive Spatter

Metal balls scattered around the weld. Usually indicates wrong settings (voltage/wire speed) or dirty base metal. Cosmetic issue but can indicate other problems.

⚠ MINOR

Uneven Bead

Width varies throughout the weld. Caused by inconsistent travel speed or shaky hand. May still pass inspection if within tolerance.

Quick Self-Inspection Checklist

  • ☐ Is the bead width consistent from start to finish?
  • ☐ Are there any visible holes (porosity) on the surface?
  • ☐ Do the edges blend into the base metal smoothly?
  • ☐ Is the weld free of cracks?
  • ☐ Is spatter minimal and limited to the weld zone?
  • ☐ Does the reinforcement look even (not too flat, not too high)?

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