Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Electrode Strength Clarification

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Rick Drake Wrote:

     In response to the Weld Electrode Strength thread I offer the 
     following additional consideration:
     The weld process is important to the design engineer if the fabricator 
     will be using the SMAW process for fillet welds.  The AISC 
     specifications (Section J.2.a in both ASD and LRFD Specs) allow the 
     use of a more generous effective throat for this process than for the 
     SAW process.  This is independent of the electrode specified tensile 
     strength. If your design requires fabrication of plate girders 
     (bridges, transfer beams, etc.), I suggest you work with the 
     fabricator to identify the process he intends to use.  He may elect to 
     use the automated, higher quality SMAW process.
     Using the effective throat appropriate for the SMAW process, you will 
     end up with smaller fillet welds than the SAW process.  Remember the 
     volume of weld material is proportional to the weld size squared.  
     Unless you are up against the AISC minimum fillet weld sizes, you can 
     save your client some money by using either t or 0.707t + 0.11 instead 
     of 0.707t for the effective throat.
     Rick Drake, SE
     Fluor Daniel, Inc.

Rick's information has some flaws in it.  Mainly SAW (sub arc welding) is the 
higher quality, automated welding process, and usually inputs higher heat 
(which results in increased penetration to the base metal) than SMAW (commonly 
referred to  as stick welding).  SAW is commonly used to join flanges to webs 
of plate girders.

Hope this info helps

Lanny Flynn