ER70S-2 0r ER80S-D2 for welding chrome molly

by Ray
(Australia)

Hi Jody
I will be welding some 4130 for a light aircraft engine mount, controls,rudder pedals etc.
I know you recommend ER70S-2 whilst some suggest ER80S-D2.

For example, more rigid welds would be best made with an ER80S-D2 classification filler rod (due to its higher tensile strength), while an ER70S-2 classification filler rod would be better suited for welds requiring more flexibility or ductility. In either instance, both filler rods offer overmatching strength (more than the 70,000 psi of the 4130 chrome-moly tubing itself). S-2 fillers clean impurities better than D-2 fillers

Should I go for the stronger ER80S-D2 rod OR for more flexibility, ductility and cleaning properties of the ER70S-2 given it will be for an engine mount? Also the ER70's are more easily obtained

Keep up the great work
Ray

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Ray,

just my opinion here...
ER70s2 will be fine. The design of the mount will probably take care of rigidity.

thanks,

jody