An incorrect weld size means the weld bead is either too big (excess reinforcement, undercut) or too small (undersized/lack of fusion/penetration), failing to meet design specifications for strength, profile (concave/convex), or depth, leading to structural weakness, cracking, or failure under load. It's a critical defect where the weld doesn't properly bond or support the intended stress, often due to incorrect parameters or technique, resulting in a structurally unsound joint.
Incorrect Weld Size or Profile
This defect is characterized by a weld bead that is either too large or too small, or has an incorrect profile. It can be identified visually or using measuring tools.
Under EN, the weld size is defined as the parameter a, which is the weld throat thickness. Under AISC (CISC), the weld size is defined as the parameter z, which is the weld leg size. You can simply calculate a from z and vice versa using the Pythagorean Theorem.
A bad weld will often be inconsistent and have visible defects. Some of the common characteristics present in a poor weld include the following: Cracks: Cracking is a common issue for welders and can occur when welding professionals apply too much pressure or if the materials cool too rapidly.
Slag inclusions and undercut are tolerated usually up to 1/8" total within a certain length of weld. Some porosity, cracks, and slag inclusions that are visible and will need further inspection to determine acceptability. Liquid Penetrant Testing (dye check) can verify minor defects.
The weld's size is determined by leg length or throat thickness, accounting for material thickness and load-bearing requirements. Fillet welds are employed in lap, T, and corner joint configurations, formed using various welding methods such as shielded metal arc welding (SMAW) or gas metal arc welding (GMAW).
We can break down weld defects into the following main categories:
These golden rules are as follows: Joint preparation is important. Welding machine set-up is the vital thing to some smooth weld. Comfort is a bit more important than welding technique.
visually acceptable, a weld shall meet the following criteria: (1) The weld shall have no cracks. (2) Thorough fusion shall exist between adjacent layers of weld metal and. between weld metal and base metal. (3) All craters shall be filled to the full cross section of the weld.
It states that fillet welds are typically sized based on the thickness of the thinner connected part, with welds between 0.25-0.5 inches thick usually requiring a 3/16 inch fillet weld and welds over 0.5 inches thick usually requiring a 1/4 inch fillet weld.
The 1G, 2G, 3G, 4G, 5G, and 6G designations in welding refer to standardized positions for welding on plates (1G-4G) and pipes (5G, 6G), indicating the orientation of the workpiece and the direction of the weld, with "G" standing for groove weld and "F" for fillet weld, representing increasing difficulty from Flat (1G) to Inclined Fixed Pipe (6G). These classifications help welders, especially in industries like construction, understand the specific skills needed for different joint types and orientations.
Fillet weld sizes are measured by the length of the legs of the largest right triangle that may be inscribed within the fillet weld cross section. Fillet weld sizes determine theoretical throat.
A uniform weld bead, flat bead, and smooth finish are positive signs. On the other hand, porosity, spatter, cracks, or an uneven surface often point to a bad weld.
Expansion and contraction of weldments is a major cause of cracking. As a component is being welded, the heat will cause a weld joint to expand. As it cools, the filler material will solidify and contract or shrink, creating internal stresses.
Defects which are welded over, and not melted out, can suffer locally intensified strain age embrittlement by static or dynamic strain ageing at the region of concentrated strain at the flaw tip, leaving a planar defect with its tip in a region of low toughness (Dawes M G).
How to Identify the 7 Most Dangerous Welding Defects
There are 4 main types of welding. Each with its own unique properties and applications. The four types of welding are gas metal arc welding (GMAW), flux-cored wire-arc welding (FCAW), shielded metal arc welding (SMAW) and gas tungsten arc welding (GTAW).
Yes, you absolutely can make $100,000 a year welding, but it usually requires specialization, advanced skills, experience, and often travel or hazardous conditions, with roles like pipeline or underwater welding offering the highest potential, though even general welders can reach this with hustle, owning equipment, and working in high-demand areas. Entry-level pay is lower, but significant growth is possible, with top earners exceeding six figures through dedication and strategic career moves.
Tungsten Inert Gas (TIG) welding is widely considered the most challenging welding process to learn. The sheer complexity of the technique requires more practice and focus to master than other less-technical welding methods.
Where combustible materials such as paper clippings, wood shavings, or textile fibers are on the floor, the floor shall be swept clean for a radius of 35 feet (10.7 m). Combustible floors shall be kept wet, covered with damp sand, or protected by fire-resistant shields.
The four basic welding positions are flat (1F/1G), horizontal (2F/2G), vertical (3F/3G) and overhead (4F/4G). Each letter tells you whether it's a fillet (F) or groove (G) weld, while the number marks the work-piece orientation. Higher codes like 5G or 6G combine challenging angles for certification tests.
Defects: Surface flaws like porosity, cracks, and undercutting are signs of poor welding.
What's the number one rule in welding? The number one thing (other than safety precautions) is always welding from the bottom up.