Welding Tips and Tricks

Can't fins this welding symbol. It is backing bar but not sure what the circle means. Anyone know?

The bevel on the root face?

I believe it’s a 45 deg angle on the plate side with an open butt with a backing strap. I’ll see if I can find confirmation.

Only other possibility is that there is a reference sheet that goes along with the drawing you picture. The circle is on the tail end so it doesn’t mean weld all the way around. That would be at a different location on the symbol. There might be or should be a separate reference where the meaning will be specifically called out. IE a Circle might mean your allowed to reinforce the weld above flush, or a square on the same point of the symbol might mean grind it flat. Point is you need the reference sheet. Whoever created the drawing should be able to provide it, butt it’s likely in the first few pages of the blueprint package, or indicated on the bottom of the drawing page which appendix it’s in.

Thx for the responses . That was just the weld symbol they had on the drawing for bidding . I had just never seen the circle at the end before.

If it’s for a bid I’d request the reference sheet. If you find out later that it’s something that requires a lot of cleanup or prep time then it could easily mean the diferance between profit and loss.

Poland308 wrote:I believe it’s a 45 deg angle on the plate side with an open butt with a backing strap. I’ll see if I can find confirmation.

I believe it’s a single bevel groove weld. Full pen with a backing bar. 45 degree angle on the bevel.

It looks like a fubar ASCII text on a CAD generated weld symbol. The little 'O' is supposed to be the degree symbol to go with the number 45 .... to say 45°(it just happens to hit the bevel symbol to appear like it has some high-falutin' meaning).

It looks like the designer has some sort of weird, overhung bevel drawn rather than the bevel getting wider as it gets higher off the backing bar.

I'm wondering how you could ensure full pen per AWS or MIL-STD-22 on a backing bar weld. Full pen typically requires grind or gouge from the opposite side until clean metal for welding from behind the root, while the purpose for backing bar is because access is only available from the exterior.