456A Welding Symbols 2 — Questions and Answers
Question 1: What information is contained in the tail of a welding symbol?
- The welder's name and certification number
- Supplementary information such as welding process, procedure specification (WPS) number, or special instructions (Correct answer)
- The date the weld must be completed
- The tail is purely decorative
Correct answer: Supplementary information such as welding process, procedure specification (WPS) number, or special instructions
The tail of the welding symbol contains supplementary information that doesn't fit in the standard symbol format. This includes the welding process designation (e.g., SMAW, GMAW), WPS number, NDE requirements, or special instructions. If no supplementary information is needed, the tail may be omitted.
Question 2: How is an intermittent fillet weld indicated on a welding symbol?
- By adding a zigzag line
- By specifying the weld length and pitch (centre-to-centre spacing) to the right of the fillet symbol, such as '6-75-150' meaning 6 mm leg, 75 mm long, 150 mm pitch (Correct answer)
- By using a dashed reference line
- By adding an X through the fillet symbol
Correct answer: By specifying the weld length and pitch (centre-to-centre spacing) to the right of the fillet symbol, such as '6-75-150' meaning 6 mm leg, 75 mm long, 150 mm pitch
Intermittent fillet welds are indicated by placing the weld length and pitch (centre-to-centre spacing) to the right of the fillet weld symbol. For example, '75-150' means 75 mm weld segments spaced 150 mm on centre. Staggered intermittent welds on both sides are shown by offsetting the symbols on the reference line.
Question 3: What does a double-V groove weld symbol look like?
- Two fillet symbols facing each other
- V-shaped symbols on both sides of the reference line, indicating the joint is grooved from both sides (Correct answer)
- A single V symbol with a '2' next to it
- Two parallel lines on the reference line
Correct answer: V-shaped symbols on both sides of the reference line, indicating the joint is grooved from both sides
A double-V groove weld is indicated by placing V-groove symbols on both sides of the reference line (one above and one below). This indicates the joint is prepared with a V-groove from both sides, typically used on thicker plates where welding from both sides ensures full penetration and reduces distortion.
Question 4: In Canadian welding standards (CSA W59), what does CJP stand for on a welding symbol or drawing note?
- Canadian Joint Procedure
- Complete Joint Penetration — the weld metal must extend through the full thickness of the joint (Correct answer)
- Certified Joint Practice
- Controlled Joint Preparation
Correct answer: Complete Joint Penetration — the weld metal must extend through the full thickness of the joint
CJP stands for Complete Joint Penetration, meaning the weld must extend through the entire thickness of the base metal at the joint. CJP welds are required for critical structural connections where the full strength of the base metal must be developed across the joint.
Question 5: What does a backing bar symbol look like on a welding symbol?
- A circle on the reference line
- A rectangle placed on the opposite side of the reference line from the groove weld symbol (Correct answer)
- A triangle at the arrow junction
- An R inside a circle
Correct answer: A rectangle placed on the opposite side of the reference line from the groove weld symbol
A backing bar is indicated by a rectangle placed on the reference line opposite the groove weld symbol. If the backing is to remain in place, the rectangle is filled; if it must be removed after welding, an 'R' is placed inside or near the rectangle. The backing material specification may be noted in the tail.
Question 6: What does the dimension placed to the left of a fillet weld symbol represent?
- The length of the weld
- The leg size of the fillet weld (Correct answer)
- The throat thickness
- The number of passes
Correct answer: The leg size of the fillet weld
The number placed to the left of the fillet weld triangle symbol represents the leg size (in mm or inches). For equal-leg fillets, a single number is given. For unequal-leg fillets, both dimensions are shown. The effective throat thickness can be calculated from the leg size or may be specified separately.
456A Welding Symbols 2
What information is contained in the tail of a welding symbol?