Wednesday, February 3, 2016

What's With Weave Width? (Woah!)

Good morning Paul,
I have a question for you.
When welding (1/8") E7018 welding rods, what's the maximum width for stringers and for weaving?  I've heard different answers but can't find anything in the D1.1 Structural Code.
Thanks and have a good day!
Ivan A.

Ivan,
For the process you mentioned, SMAW (E7018), you will not find many restrictions on weave/oscillation width. Table 3.6 in Clause 3 - "Prequalification of WPS's" limits the maximum size of single pass fillet welds to somewhere between 5/16" and 1/2" depending on the position.  That would be a limitation on weave width.  Table 4.6 in Clause 4 - "Qualification" would also limit weave/oscillation width in Charpy V-Notch Testing (CVN) applications by limiting heat input and weld metal volume (see: Electrical Characteristics 9).  Travel Speed plays a key role in both those calculations and weave width has a direct impact on travel speed (the wider the weave, the slower the weld progression, or travel).
With other processes (GMAW, FCAW...) weave width would be governed by the Weld Size and "Split Layer" limitations of Table 3.6, the travel speed (see: 19) limitations of Table 4.5, and the Heat Input/Volume (9) limitations of Table 4.6
Over the years as the "Weld Engineer" on specific projects I've come up with weave width limitations that I have found to work in my applications.  They were not limitations listed on a Weld Procedure Specification (WPS) because of a code requirement, they were listed on the WPS because of the "Engineers" requirement (mine).
I'm sure you came looking for a "hard" number you could use to determine weave or oscillation width.  But that is a number that you would need to calculate given your specific requirements.
PWC