Meaning of penetration

[FIREFLY737]

Thank you in advance for previous posts, I'm learning a lot. Can someone help me understand the meaning of penetration as it relates to the different rods. E6011 and E7018, for example, the E6011 penetration is considered a deep penetrating rod vs. the E7018 a low penetrating rod. Why are welders using the 7018 on the initial pass?

Mahalo, Isaac

[Bert]

For work and school we used 6011 for the root pass and cover with 7018. From what I hear, 6011 is deeper penetrating, but they want the 7018 'cause it has 10,000 more tensile stregnth than 6011. Lot of guys I know do everything with 7018.

[Bert]

Oh, sorry...also, 6011 burns through paint, surface rust and galvanized. For 7018, metal has to be clean. Doesn't burn as deep, but it's stronger.

[mwccwi]

Thank you in advance for previous posts, I'm learning a lot. Can someone help me understand the meaning of penetration as it relates to the different rods. E6011 and E7018, for example, the E6011 penetration is considered a deep penetrating rod vs. the E7018 a low penetrating rod. Why are welders using the 7018 on the initial pass?

Mahalo, Isaac

The Miller web page has a section in resources that can provide you with better understanding of electrode characteristics. As for, "Why are welders using the 7018 on the initial pass?" Usually the E6010/6011 type rods are used for open roots (the fast freeze properties allow for more ease in bridging the gap combined with the additional penetration help assure sound roots) the E7018 lo/hy rod are usually use in root with backing or that are back gouged and rewelded.

[paulrbrown]

Fellas, it is not the penetration that makes 6010 and 6011 the rod to use on open roots, it is the CO2 gas shield created by the Cellulose in the covering. Other rods depend on a slag covering to keep O2 out of the weld. Hope thisis of some use, Paul

[Darmik]

Why are welders using the 7018 on the initial pass?

When you say inital pass what do you mean?the very first pass after the root or the root it's self?
In the XX18 series rods you can do very good roots with this however you must use the 9018-B3 rod in dcen first root pass then you fill and cap with dcep 6010 and 6011 are what pipe welders use typicaly for roots.hope this helps ya

[paulrbrown]

What I forgot to mention was the back of the weld root, it is exposed to the atmosphere, no slag to protect the weld metal, that is why pipe and open groove welds require a 6010 or 6011 root pass. Paul