Visual Inspection Criteria
The following criteria are based on industry standards and accepted codes, but are not intended to be understood as code themselves. The following are intended to aid the student and instructor in evaluating lab assignments and assigning grades to those assignments. Specific points are not assigned for each criterion; rather, the lab coupons are compared to these criteria as a whole.
Visual Acceptance Criteria for Thermal Cutting
| Aspect | Unacceptable | Acceptable | Outstanding |
| Square to Top | Majority of cut alternates between acute and obtuse angles rather than prescribed angle | Majority of cut follows prescribed angle | No easily detectable deviation from prescribed angle |
|---|---|---|---|
| Smoothness of Kerf | Cut is jagged, kerf lines indicate improper travel speed, or excessive dross | Great majority of cut is smooth, kerf lines indicate proper travel speed, little dross that is easily removed | No jagged edges on cut, texture is uniformly smooth with kerf lines less than 1/64” in depth |
| Follows Layout Lines | Cut generally deviates from layout lines | Great majority of cut follows layout lines | Any deviations from layout are difficult to detect |
| Top Edge of Cut | Top edge is rounded, with melted appearance or bubbled up dross | Majority of cut has “crisp” top edge | Entire top edge of cut has “crisp” top edge |
Visual Acceptance Criteria for Fillet Welds
| Aspect | Unacceptable | Acceptable | Outstanding |
| Defects/Discontinuities | More than 5% of weld shows any of the following: Lack of fusion, overlap, slag inclusion, undercut, crater cracks, underfill, porosity, arc strikes outside weld joint | No overlap, cracks, slag inclusions, or underfill. No more than 5% of weld shows undercut exceeding 1/32” in depth, minor porosity, no more than 1/8” face reinforcement | No visible defects, no easily detectable or measurable discontinuities |
|---|---|---|---|
| Leg Length | Excessive difference in leg lengths, alternating leg lengths resulting in face of weld having a “twisting” appearance | Leg length nearly equal, consistent for length of weld. Face of weld is in “plane” for length of weld | Leg length is equal for length of weld |
| Throat* | Degree of concavity or convexity is visibly greater than 1/8” | Degree of concavity or convexity is visibly between 1/16” and 1/8” | Degree of concavity or convexity is visibly less than 1/16”. Thickness of throat is uniform entire length of weld |
| Bead Width | Width varies greatly from one end of bead to other. SMAW Bead exceeds width of 2 electrodes, GMAW/FCAW bead exceeds 10 wire diameters in width | Majority of weld bead is consistent in width, SMAW Bead does not exceed width of 2 electrodes, GMAW/FCAW bead does not exceed 10 wire diameters in width | Entire weld bead is consistent in width, SMAW Bead does not exceed width of 2 electrodes, GMAW/FCAW bead does not exceed 10 wire diameters in width |
| Ripples | Narrow “V” shape, too hot. Wide “C”, too cold, slow | Much of weld bead shows consistent ripples, “C” shapes evenly spaced | Entire weld bead shows consistent ripples, “C” shapes evenly spaced |
| Multi-Pass Weld Tie-In | Weld beads show distinct separation between each other, crevices between crowns of weld beads | Weld beads overlap each other by at least 25%, minimal lows between crowns | Weld beads overlap each other by 50%, toe of each weld bead lies at center of previous bead. Surface of the weldment is smooth |
* Note: Throat is measured from the hypotenuse of toes to the root.
Visual Acceptance Criteria for Groove Welds
| Aspect | Unacceptable | Acceptable | Outstanding |
|---|---|---|---|
| Defects/Discontinuities | More than 5% of weld shows any of the following: Lack of fusion, overlap, slag inclusion, undercut, crater cracks, underfill, porosity, arc strikes outside weld joint | No overlap, cracks, slag inclusions, or underfill. No more than 5% of weld shows undercut exceeding 1/32” in depth, minor porosity, no more than 1/8” face reinforcement | No visible defects, no easily detectable or measurable discontinuities |
| Throat* | Degree of concavity or convexity is visibly greater than 1/8” | No concavity or underfill. convexity is visibly between 1/16” and 1/8” | No concavity or underfill. convexity is visibly between 1/16” and 1/8” Thickness of throat is uniform entire length of weld/joint is completely filled |
| Bead Width | Width varies greatly from one end of bead to other. SMAW Bead exceeds width of 2 electrodes, GMAW/FCAW bead exceeds 10 wire diameters in width | Majority of weld bead is consistent in width, SMAW Bead does not exceed width of 2 electrodes, GMAW/FCAW bead does not exceed 10 wire diameters in width | Entire weld bead is consistent in width, SMAW Bead does not exceed width of 2 electrodes, GMAW/FCAW bead does not exceed 10 wire diameters in width |
| Ripples | Narrow “V” shape, too hot. Wide “C”, too cold, slow | Much of weld bead shows consistent ripples, “C” shapes evenly spaced | Entire weld bead shows consistent ripples, “C” shapes evenly spaced |
| Multi-Pass Weld Tie-In | Weld beads show distinct separation between each other, crevices between crowns of weld beads | Weld beads overlap each other by at least 25%, minimal lows between crowns | Weld beads overlap each other by 50%, toe of each weld bead lies at center of previous bead. Surface of weldment is smooth |
* Note: Throat is measured from the hypotenuse of toes to the root.
