What does the AWS electrode number mean?

In a number like E7018 the first two digits are the minimum tensile strength in ksi, so 70 means 70,000 psi. The third digit is the welding position, where 1 is all positions and 2 is flat and horizontal only. The last digit encodes the flux coating type and the current or polarity.

When should I use E7018 instead of E6010 or E6013?

E7018 is a low-hydrogen electrode used for structural and code-quality work because its dry basic flux keeps hydrogen out of the weld and prevents cold cracking. E6010 and E6011 are deep-penetrating cellulosic rods for root passes and dirty plate, while E6013 is a soft, shallow rod for thin sheet.

Which electrode welds stainless steel?

Match the grade: E308L for 304 stainless, E316L for 316, and E309L for dissimilar joints such as carbon steel to stainless or for clad transitions. The L means low carbon, which limits chromium-carbide precipitation and keeps the heat-affected zone corrosion resistant.

Does this replace a welding procedure specification?

No. It is a fast reference for selecting a starting electrode. The governing WPS for your code, such as AWS D1.1 or ASME Section IX, always overrides a quick-pick table and defines the qualified essential variables for your joint.

Why does deep penetration need cellulosic electrodes?

Cellulosic coatings like those on E6010 and E6011 burn off cellulose to produce a forceful, hydrogen-rich arc that digs deep and cuts through rust, mill scale, and poor fit-up. That makes them the standard choice for pipe root passes and field repairs.

Stick Electrode Selection Guide

Choosing the right stick (SMAW) electrode is the single biggest decision in manual arc welding. The electrode controls penetration, mechanical strength, hydrogen content, and how forgiving the arc is on dirty or out-of-position joints. This tool maps the three variables that matter most — base metal, welding position, and penetration need — to a specific AWS classification, then explains the flux and polarity behind it.

How it works

AWS A5.1 classifies carbon-steel electrodes with the pattern E-XX-Y-Z:

E 70 1 8
| |  | |
| |  | +-- coating type + current/polarity
| |  +---- position: 1 = all, 2 = flat & horizontal
| +------- (two digits) tensile strength in ksi: 70 = 70,000 psi
+--------- E = electrode

The last digit ties the coating to the current. Cellulosic coatings (E6010 sodium on DCEP, E6011 potassium on AC or DCEP) give a deep, digging arc. Rutile coatings (E6013) give a soft, shallow, easy arc. Basic low-hydrogen coatings (E7018) give medium penetration with the lowest crack risk, which is why they dominate structural steel.

For stainless and dissimilar metals the tool switches to AWS A5.4: E308L to match 304, E316L to match 316, and E309L for carbon-to-stainless and clad joints, where its high chromium and nickel survive dilution from the carbon-steel side.

Tips and notes

Keep low-hydrogen electrodes (the 18 family) dry. Once the airtight can is opened they must live in a heated rod oven; damp flux reintroduces the hydrogen the coating exists to avoid.
On rusty or painted plate, reach for E6011 — it tolerates contamination far better than E6013 or E7018.
For all-position root passes on pipe, E6010 on DCEP is the classic. On a cheap AC buzz-box that cannot strike it, E6011 is the equivalent.
The strength digits are a minimum. A 70-series electrode overmatches A36 or S275 base steel, so the base metal, not the weld, is usually the limiting factor.