Weld symbol
Flush contour symbol
A straight bar drawn across the outer face of a weld symbol calls for the finished weld face to be level with the adjoining surfaces rather than left with its natural reinforcement.
Reads asArrow side: V-groove weld, 1/2 size, 60° groove angle, flush contour, finish method G.
How to read it
The contour symbol is drawn just beyond the weld symbol's outer face, on the same side of the reference line. When it is a straight bar, the requirement is a flush face: the finished weld is to sit level with the surrounding base metal rather than standing proud with the crown a weld naturally forms.
A bar on its own says what shape is wanted but not how to get there. That is the job of the finish letter written alongside it. Without a letter, the flush face may be produced by welding technique alone, which is achievable on some processes and positions and unrealistic on others. With a letter, the method is fixed and there is no argument on the shop floor about grinding versus machining.
Flush faces are asked for when something has to sit against the weld, when flow across the surface must not be disturbed, or when the joint sees fatigue loading and the abrupt change in section at a weld toe would concentrate stress. Removing the reinforcement smooths that transition considerably, which is why fatigue-critical joints so often carry this bar.
There is a cost to it. Dressing a weld face flush removes the reinforcement that gives a joint its margin, so a weld ground flat must be full and sound underneath before dressing, not built up and then cut back. Grinding into the base metal below the surrounding surface turns a finishing operation into a defect, which is why depth control matters as much as the shape.
Where each dimension goes
- Straight bar beyond the weld symbol
- Calls for the finished weld face to be level with the adjoining base metal surfaces.
- Position of the bar
- It sits just past the weld symbol's outer face on the same side of the reference line, so it applies to that side's weld.
- Finish letter
- Written with the bar to name the method used to reach the flush face, such as grinding or machining.
- Both sides
- Each side of the reference line carries its own contour, so one face can be dressed while the other is left as welded.
Worked examples
Each one is a drawing, the sentence it comes out as, and then the mark-by-mark account of why. Read the sheet first and say the sentence yourself before you look down.
Example 1: Butt weld ground flush both faces
TitleButt weld ground flush both facesRefFlush contourEx1 / 2Reads as
Fill the vee and grind both faces of the weld level with the plate.
Which mark says so
- V-groove symbolBelow the reference lineA V-groove weld on the arrow side of the joint
- 1/2Left of the arrow-side symbolGroove weld size - how deep the weld itself goes
- 60°Beyond the outer face of the arrow-side symbolIncluded angle the joint is prepared to
- flush contourBeyond the outer face of the arrow-side symbolThe completed face is to be flush
- GBeyond the contour on the arrow-side symbolThe method used to reach that contour, not the finish itself
- back symbolAbove the reference lineA back weld on the far side of the joint
- flush contourBeyond the outer face of the other-side symbolThe completed face is to be flush
- GBeyond the contour on the other-side symbolThe method used to reach that contour, not the finish itself
A bar with a G appears on each side of the reference line, so both the front and back faces of the completed joint are dressed level rather than left with reinforcement.
And what it does not say
- No length is given, so each weld runs the full length of the joint.
- There is no circle at the elbow, so the weld does not continue around the joint.
Example 2: Flush face on one side only
TitleFlush face on one side onlyRefFlush contourEx2 / 2Reads as
Grind the arrow-side face flush and leave the far side as welded.
Which mark says so
- bevel-groove symbolBelow the reference lineA bevel-groove weld on the arrow side of the joint
- 3/8Left of the arrow-side symbolGroove weld size - how deep the weld itself goes
- 45°Beyond the outer face of the arrow-side symbolIncluded angle the joint is prepared to
- flush contourBeyond the outer face of the arrow-side symbolThe completed face is to be flush
- MBeyond the contour on the arrow-side symbolThe method used to reach that contour, not the finish itself
- fillet symbolAbove the reference lineA fillet weld on the far side of the joint
- 1/4Left of the other-side symbolLeg size of the fillet
Only the lower symbol carries a bar, so only that face is dressed. The far side keeps its natural reinforcement, which is common where only one surface has to seat flat.
And what it does not say
- No length is given, so each weld runs the full length of the joint.
- There is no circle at the elbow, so the weld does not continue around the joint.
Common mistakes
- Grinding into the base metal below the surrounding surface while chasing a flat face.
- Building reinforcement up and then cutting it back rather than depositing a sound, full weld first.
- Applying the contour to both faces when only one side of the reference line carries the bar.
- Ignoring the finish letter and choosing a method the drawing did not intend.