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RE: WE-Electrode Strength -Reply

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If I were choosing an electrode strength, I would consider AWS D1.1
Table 3.1.  This Table, which is applicable to all welds, tells which
strength electrode matches various base metal strengths so that a
prequalified welding procedure may be used. If the base metal strength
and filler metal strength do not match, the welding procedure will have to
be qualified by test (PQRs) and that will incur added expense. Sometimes
this is necessary but there should be a good reason for it IE
fabricator/erector already has the  PQR done, improved joint design etc.

The common process, FCAW,  is not prequalified with 60 ksi strength
electrodes.  A minimum of 70 ksi is required. Most strength steels (AWS
Group I,II ) are prequalified at 70 ksi although Group III  steels (IE
A572-60) requires 80 ksi. Unless there is a specific reason to the
contrary, I would specify the prequalified matching filler metal strength
for the grade of steel I am using and design the weld accordingly.

To help insure the proper weld strength, I would specify the required
strength in the material specifications and require the Welding Procedure
Specifications (WPS) and specific electrode data from the manufacturer
to be included in the shop drawing submittal. Weld strength verification is
also the duty of the quality control (fabricators/erectors)  and quality
assurance (owners) inspectors.

Hope this helps.

Tim McCormick, P.E.
City of Los Angeles
Department of Building & Safety