weld symbol clarification

By TimGary (****)

Date 01-28-2015 19:31

It's a slot weld, so the correct symbol would be a plug weld symbol with .22 on the left and 1.78 on the right.
You could also include pitch distance between centers of slots by putting on the right side of the plug weld symbol 1.78 - pitch, and a flat line contour symbol with a G to indicate grind flush.

Tim

By welderbrent (*****)

Date 01-28-2015 20:44

bbarber,

WELCOME TO THE AWS WELDING FORUM!!

I agree with Tim. Had to since he called it perfect with A2.4:2012 Standard Symbols for Welding, Brazing, and Nondestructive Examination.

If you were not filling it to the top you would include the desired depth of filling inside the Plug/Slot Weld rectangular box. See pages 58 and 63 for text and 59-62 and 64-66 for illustrations.

Also, if you look at Clause 10.1.4 on page 63 along with Clause 8.5 on page 57 with Figure 34(A) on page 56 you can see why the fillet weld symbol is not correct for your application. Even if you were not filling the slot clear to the top you would only use the fillet weld symbol if the slot were wide enough to make a distinct fillet weld in the slot.

So, since the same symbol is listed for both I prefer to call it after the name of the particular application. Thus, the correct weld symbol on the welding symbol is the Slot weld rectangular box with .22 on the left and 1.78 on the right to indicate the weld dimensions. Being filled to the top nothing is required inside the box but you would want to include the straight line indicator over the box with a 'G' over that to indicate that it is to be ground flush.

Now, this is true regardless of the applicable codes if AWS welding symbols are applicable to the job at hand. If being done for different organizations codes you would want to make sure they still acknowledge AWS welding/weld symbols as the acceptable standard. European symbols can differ as well as some ISO symbols. But overall, this information will be correct.

He Is In Control, Have a Great Day, Brent

By bbarber Date 01-30-2015 02:40

Brent-

First, thank you for all of your references and the time you took to provided them. It all makes perfect sense if the fundamental definition of a slot weld were met.

AWS D 1.1 (2010)
2.4.5.3 Effective Area of Plug and Slot Welds. The effective area of a plug and slot welds shall be the nominal area of the hole or slot in the plane of the faying surface. The key phrase her is FAYING surface.

The definition of a faying surface combined with every illustration (eg Fig 37 and Fig 38 from ASW D2.4 (1998) pages 64 and 65) I have found used to describe slot welds disqualifies my example from any further consideration of establishing parameters as you and Tim have described. Please let me know your thoughts.

Thanks so much!

Brian

By TimGary (****)

Date 01-30-2015 13:36

Hello Brian,

My slot weld call out was based on a simplistic definition that while fillet welds maybe be placed around the inside of a slot, if you completely fill the slot than a slot weld symbol would better describe the weld.
Once we invoke AWS D1.1 however, there are additional restrictions.
In D1.1:2010, sections 2.4.4.1 for fillet welds in slots and 2.4.5.1 for slot welds both state that "The minimum diameter of the hole or slot shall be no less than the thickness of the part which it is made plus 5/16". Also 2.4.5.2 states that "The ends of the slot shall be semicircular or have the corners rounded to a radius not less than the thickness of the part in which it is made."
So, it appears that the slot design detail in the sketch you provided does not meet these minimum requirements.
There may also be PQR and WPQR concerns if your Welder is only fillet weld certified. See 4.15 and 4.30.

I would assume (knowing that "assume" is a dangerous word, but free advice is worth what you pay for it) that these design restrictions are based on the chance that the root stress riser created by your detail would place the partially inserted tab at risk of pulling out of the part if placed under too great of a load.
Perhaps (which is another dangerous word) this joint could be reinforced in a manner to make a code exception acceptable to your Enginner by placing a reinforcing fillet around the tab on the opposite side of the plate from the slot?
Looks like we've opened a can of worms.
I bet Brent will have a better reply.

Tim

By bbarber Date 02-03-2015 15:45

Thank you very much for taking the time to respond.

By welderbrent (*****)

Date 01-30-2015 14:50

Thanks for the compliment Tim but you do very well by yourself. And then our most senior expert stepped in quite nicely with the points I should have caught right off the bat.

Brian, thanks for giving us your name, this is, as Al explained, another one of those situations we run into quite often. The weld symbols are not 100% fool proof and all inclusive. A major one that comes up very often is dealing with skewed joints were the weld is not truly a fillet weld any longer and the D1.1 states that in certain cases the detailer is obligated to include a detailed drawing showing the fabricator exactly what the intention is.

The obligation for this is found in D1.1, Clause 2.3.5 and 2.3.5.5. You can also refer through that area of Clause 2 to the skewed weld examples for a specific idea of how details make all the questions go away where the standard symbols just don't apply.

Now, the bottom line based upon your original query comes down to this not being a fillet weld. That is the first option to eliminate. From there, for a pure defining of application, you have also now eliminated the slot weld as well (though that would be closer but close only counts in horseshoes and hand grenades of which we are not dealing with either one). So, we come back to the sketch that is the only sure way of truly describing what the intent of the engineer and/or detailer is.

He Is In Control, Have a Great Day, Brent

By bbarber Date 02-03-2015 15:45

Thank you very much for taking the time to respond.

By 803056

Date 01-30-2015 14:06 Edited 01-30-2015 14:10

"When in doubt, sketch it out."

This is not truly a slot weld as defined by AWS D3.0. I agree a slot weld is the closest standard joint the geometry the detail resembles, but the detail includes a component that extends into the joint a short distance.

I have no doubt that most people would interpret the symbol to mean, fill the slot to the specified depth with the weld. However, if you have any concerns, use a reference line with the arrow pointing to the joint and include a reference to a separate detail in the tail. The detail should show the required configuration with the required weld shaded in. It is hard to argue the intent when there is a sketch indicating the require dimensions and depicting the required weld requirement.

Welding symbols are sufficient for 90% of the welds used by industry, but they may not be sufficient for the remaining 10%. A sketch should be used where a standard welding symbol simply doesn't convey the required information.

In your case, your drawing already includes a section view of the joint detail, simply add the cross section of the required weld, add Detail X-X to the section, and place the welding symbol to the plan view.

Best regards - Al