Weight per inch table for standard welds ?

[cfee]

Hello ! I'm over from the AutoCAD forum with a little bit different question-

We have a fairly large welded structure and would like to estimate the added weight of all of the welds. My opinion is that the difference would be insignificant, but there are other "wiser" opinions that want to be sure, so I started a search. A standard internet search turned up no effective solution.

Thoughts ?

Thanks !

CFee

 

[DBronson]

cfee:

There are tables on pages 7.5-3,4,5, & 6 of Omer Blodgett's book "Design of Welded Structures" that have the weight per foot of weld for various types of welds.

Regards,

DB

 

[kingnero]

isn't this basic geometry and knowing that steel weighs almost 8 times as much as water?

 

[Crannog]

If you want a ball-park figure I've found 5% of total structural-steel weight to usually be about right, but that is dependent on fabrication type. On a low welding application I would use 5% to capture weld + paint.

If you have prior history of this type of fab you can keep and eye on how much welding wire it going into one. Then if you have chance to weigh/lift the fab at the end of the project, or better once structural work is complete you can compare your estimates for the work your doing.

-Drew

 

[Tmoose]

Is the goal a more accurate component weight estimate?
Or, for estimate of how much weld filler to buy?

I'm thinking use of fillet welds would add "something."
But full penetration welds would be largely replacing material removed in the V, J, etc weld prep.

 

[racookpe1978]

Tmoose: Your observation about the final added "volume" of the final weld (after ALL weld prep's are completely filled, is the only way to estimate "added weight" after welding.

Weld metal density is so close to forged metal or cast steel or rolled steel so as to make no difference at all. So, if the weld prep's are filled in, then the joint has no change in weight of the simplified volume of the two pieces of metal.

Fillet welds add a one-for-one weight gain. Drilled holes are a one-for-one volume reduction. Bolted holes (riveted if you use those) lose the hole volume, but gain the extra weight of the washer+bolt head+ nut + exposed threaded length. Which is not much unless you're doing rocket or helicopter weights.

On the other hand, I regularly find CAST metals are larger in metal volume (weight) than the roginal design assumptions. Maybe because castings are estimated by drawing volumes, but paid for by weight-of-metal?