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Re: WE-Electrode Strength -Reply

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Most engineers specify " E70xx" for filler metals to convey to the
fabricator/erector that 70 ksi strength is required.  However, this
designation also specifies process since only stick welding (SMAW)
uses both numbers in the electrode designation.  The more common flux
cored arc welding electrodes use only the first number to designate
strength in units of 10 ksi. The second number indicates allowable
welding positions. Because fabricators/erectors understand that
engineers do not usually specify process and the E70xx requirement is
meant to designate strength only, they will ignore this anomaly and use
the most advantageous welding process they are qualified for.

The more accurate electrode specification is strength alone. IE. 70 ksi
tensile strength. You may also wish to specify low hydrogen (most but
not all electrodes are) and Charpy V-Notch impact requirements. These
requirements normally appear in the material specifications and not on
approved drawings although some engineers may show where
notch-tough weld material is required on details when it is not used
throughout. This may also be done in shop drawing approvals.

Review of the fabricator/erector's Welding Procedure Specifications and
familiarity with AWS electrode specifications (AWS 5.20- FCAW, AWS
5.1- SMAW, AWS 5.18- GMAW) will help ensure that your design intent
is realized.

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