456A Welding Symbols — Questions and Answers
Question 1: On a welding symbol, what does the arrow side versus the other side indicate?
- Arrow side is for tack welds; other side is for finish welds
- The arrow side refers to the joint surface the arrow points to; the other side refers to the opposite surface of the joint (Correct answer)
- Arrow side is always the top; other side is always the bottom
- There is no distinction between arrow and other side
Correct answer: The arrow side refers to the joint surface the arrow points to; the other side refers to the opposite surface of the joint
In CSA W59 and AWS A2.4 welding symbol conventions, the arrow side is the joint surface that the arrow physically points to. The other side is the opposite surface of the same joint. Weld symbols placed below the reference line indicate arrow-side welds; symbols above the reference line indicate other-side welds.
Question 2: What does a fillet weld symbol look like on a welding drawing?
- A circle on the reference line
- A right triangle placed on the reference line with the vertical leg always on the left (Correct answer)
- A V-shape on the reference line
- A horizontal line through the reference line
Correct answer: A right triangle placed on the reference line with the vertical leg always on the left
The fillet weld symbol is a right triangle with the perpendicular (vertical) leg always on the left side, regardless of the weld orientation. The leg size is written to the left of the symbol. This is the most commonly used welding symbol in structural and general fabrication.
Question 3: What does a circle at the intersection of the reference line and arrow indicate on a welding symbol?
- A spot weld is required
- The weld must go all around the joint (weld-all-around) (Correct answer)
- The weld requires field inspection
- A plug weld is required
Correct answer: The weld must go all around the joint (weld-all-around)
A circle placed at the junction where the arrow meets the reference line indicates a weld-all-around symbol, meaning the weld must be applied continuously around the entire joint. This is common for pipe connections, circular attachments, and perimeter welds on structural connections.
Question 4: What does a flag (triangle) at the intersection of the reference line and arrow indicate?
- The weld must be ground smooth
- The weld is to be made in the field (on site) rather than in the shop (Correct answer)
- The weld requires pre-heat
- The weld must be done in the overhead position
Correct answer: The weld is to be made in the field (on site) rather than in the shop
A flag (small filled or open triangle) at the junction of the arrow and reference line indicates a field weld — one that must be performed at the construction site rather than in the fabrication shop. This is critical information for planning, as field welds may require different procedures and inspection.
Question 5: On a groove weld symbol, what do the numbers inside and outside the weld symbol indicate?
- Inside is the weld length; outside is the number of passes
- The number inside the groove symbol indicates the groove angle; the number to the left indicates the depth of groove or weld size (Correct answer)
- Inside is the electrode size; outside is the amperage
- Numbers are only used for fillet welds
Correct answer: The number inside the groove symbol indicates the groove angle; the number to the left indicates the depth of groove or weld size
For groove weld symbols, the number inside the V or U shape indicates the included groove angle in degrees. The number to the left of the symbol indicates the depth of groove preparation or the effective weld size. Additional dimensions like root opening and root face appear in parentheses or between the symbol and reference line.
Question 6: What does a supplementary contour symbol (straight line, convex arc, or concave arc) added to a weld symbol indicate?
- The direction the welder should travel
- The desired surface profile of the finished weld — flat (flush), convex (crowned), or concave (dished) (Correct answer)
- The type of filler metal to use
- The number of weld passes required
Correct answer: The desired surface profile of the finished weld — flat (flush), convex (crowned), or concave (dished)
Contour symbols are placed above or below the weld symbol to specify the desired finished weld profile: a straight line indicates flush/flat, a curved line bulging outward indicates convex, and a curved line dishing inward indicates concave. A letter next to the contour symbol indicates the finishing method (G for grinding, M for machining, C for chipping).
456A Welding Symbols
On a welding symbol, what does the arrow side versus the other side indicate?