The maximum size of fillet weld applied to the square edge of a plate of thickness greater than 6 mm is
- ANot more than the thickness of plate
- B1.0 mm less than the thickness of plate
- C1.5 mm less than the thickness of plateCorrect
- DHalf the thickness of plate
Solution
Concept
Maximum size of fillet weld on plate
Formula
Max size = t - 1.5 mm
Step-by-step solution
1. According to IS 800:2007 clause 10.5.8.1, maximum fillet weld size depends on plate thickness. 2. For square edges of plates greater than 6 mm thick, weld size is restricted to avoid burning off edge corners. 3. The maximum size of fillet weld is 1.5 mm less than the thickness of the plate. Answer: C
Explanation
According to IS 800 standards for steel design, the maximum size of a fillet weld applied to a square edge of a plate thicker than 6 mm should be 1.5 mm less than the plate thickness. This margin prevents the exposed sharp corner of the plate from melting away during welding, ensuring proper weld root profile and structural integrity. For rounded edges, it is restricted to three-quarters of the plate thickness.
Why the other options are wrong
A) Setting maximum weld size equal to plate thickness applies to rounded or rolled edges. B) The reduction factor for square edge plate thickness is 1.5 mm, not 1.0 mm. D) Half the plate thickness is not a standard maximum limit for fillet welds on square edges.
Shortcut
Max fillet weld size for square edge = Plate thickness minus 1.5 mm.
Common mistake
Confusing the 1.5 mm deduction for square plate edges with the 3/4th thickness rule for rounded toes.
Correct answer: C) 1.5 mm less than the thickness of plate