AWS D17.1 Help with interpretation for fillet welds

By Ernest Mayer Date 03-31-2008 15:54

Help? Anyone?

By Lawrence (*****)

Date 03-31-2008 18:11

Ernest,

I would ask "whoever brought up the subject" to show you which specificic passages from table 6.1 shall be excluded from your welder performance qualification test samples.

There is a astrick noted for incomplete penetration in Table 6.1, but that type defect is adequatly covered in 4.3.8.2

You might also elect to overlook some craters, or other discontinuities on fillets if they are at the ends (1/2 inch) of the fillet welds as noted in 4.8.3.1

I think if you can detail exactly what these folks think should not be applied out of 6.1 we will have more to talk about here.

By Ernest Mayer Date 04-02-2008 14:47

Lawrence,

Thank you for your reply.
The "Welding Engineer" said that it is "understood" that the section on Concavity does not apply to fillet welds. I have AWS 3.0 for Welding Terms and Definitions, and it clearly shows a diagram defining, among other things, a measurement for concavity of a fillet weld. (I believe it is page 83). When I asked him where this was documented, he said "You will have to trust me", because of his 20+ years experience as a welder. I then told him that I am a testing authority, and unless the requirements were more specific from the customer, I did not see where his interpretation was documented and I therefore did not have the authority to interpret the D17.1 requirements in that manner. He did not like that answer.
So I am trying to find out if there is something, somewhere, that I have missed, that he could not articulate to me.

By Lawrence (*****)

Date 04-02-2008 18:52 Edited 04-02-2008 20:23

Earnest,

Now I think I can help you.

When you/he are talking about concavity of a fillet weld... Are you asking about concavity on the front side of the fillet where the filler is applied or are you talking about concavity the back side of the fillet, opposit of the side that filler is added, the non standard term would be "suck back".

With thin Aerospace sheet metals suckback can be quite a problem, It used to be addressed specifically in older versions of Mil Std 1595, is it possible that your seasoned engineer is thinking about that?

If you are talking about concave profiles on the front side of a fillet than the text is pretty clear.. The weld size will be measured by the triangle that fits inside the macro section..... If the weld is concave to the extent that the requred weld size is not achieved than it is undersized. If the concave profile when sectioned and measured is adequate (a large enough triangle) than the thing is good.

Now as far as D17 table 6.1 speaks specifically to "concavity" it really does NOT relate much to fillets in my opinion. The proper term in D17 for an overly concave fillet profile would be "Insufficient Throat" or "Insufficient Leg Size"

Look to D17 Table 6.1 Fillet weld size-minimum size when fillet weld size is not stated in the drawing
Here you will find the minumum weld sizes. Again these sizes will be figured from your macro sections. (See Figure 6.1 (C) Unacceptable Fillet weld Profiles INSUFFICENT THROAT)

Here is an interesting note... D17 Figure 6.1 uses a triangle calculated from the root, "theoretical throat" to measure weld size (just look at the picture). While A3.0 2001 Figure 25 (B) calculates weld size in a concave fillet using the Actual/Effective throat. Note D17 Commentary C3.3.3 second paragraph

I think the D17 Table 6.1 reference to "concavity" is speaking to defects illustrated in Figure 6.1 (E) Insufficient Throat

Regardless of Weld Class; The minimum weld size must be 1.5T on a single sided fillet right? Whether the fillet has a concave, flat or convex profile.

Let me know what happens next

By Ernest Mayer Date 04-14-2008 19:00

Thank you very much for the reply. I will check this out thoroughly and let you know what happens.

Ernest