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Stick Electrode Classifications (AWS A5.1 and A5.5)

How to read a covered (stick) electrode classification such as E6010 or E7018-1 H4R digit by digit, and what the suffixes tell you about toughness, hydrogen and alloy.

Ref WG-0102AWS A5.1AWS A5.5AWS D1.1

Draft, open for review. Check every value against the governing standard and the manufacturer’s data before use.

What it is

Carbon steel shielded metal arc welding (SMAW) electrodes are classified under AWS A5.1; low-alloy steel electrodes under AWS A5.5. The classification is printed on each rod near the grip end and on the package. It encodes minimum weld-metal tensile strength, usable welding positions, and the coating type with the current it runs on. Optional suffixes add toughness, diffusible hydrogen, moisture-resistance or alloy information.

How to identify

E = electrode.
First two digits (or three for strengths of 100 ksi and up) = minimum tensile strength in ksi. E70xx = 70 ksi.
Next digit = positions: 1 all positions; 2 flat and horizontal fillet only; 4 flat, horizontal, overhead and vertical-down.
Last two digits together = coating type and current.

Common carbon steel electrodes

Classification	Coating type	Current	Typical use
E6010	High cellulose, sodium	DCEP	Deep penetration, pipe root passes, dirty steel
E6011	High cellulose, potassium	AC or DCEP	Like 6010 but runs on AC machines
E6013	High titania, potassium	AC, DCEP or DCEN	Light gauge, sheet metal, good appearance
E7014	Iron powder, titania	AC, DCEP or DCEN	Higher deposition, easy to run
E7018	Low hydrogen, potassium, iron powder	AC or DCEP	Structural work, crack-sensitive steels, code work
E7024	Iron powder, titania	AC, DCEP or DCEN	Fast flat and horizontal fillets

Suffixes

Suffix	Meaning
-1 (e.g. E7018-1)	Improved low-temperature impact toughness (A5.1 option)
H4 / H8 / H16	Diffusible hydrogen limit in mL per 100 g of deposited weld metal
R	Meets the absorbed-moisture test after humid exposure (moisture resistant)
-A1, -B2, -B3, -C1, -C3, -D1, -G (A5.5)	Alloy family designators (e.g. carbon-moly, chrome-moly, nickel, manganese-moly, general)
-M (A5.5)	Military-requirement classification

Key points

Low-hydrogen electrodes (EXX15, EXX16, EXX18) must be stored and reconditioned per the manufacturer and the governing code; AWS D1.1 limits atmospheric exposure time.
A classification sets minimum properties; brands differ in arc feel and actual mechanical results. Code work may require the specific brand/type on the WPS.
Electrode diameter is a separate attribute, ordered alongside the classification.
AWS A5.1/A5.1M also lists metric classifications (for example E4918 corresponds to E7018). Match the form used on the customer's WPS.

Common mistakes

Substituting E6013 for E7018 on structural work because both are "70-ish".
Running E6010 on an AC-only machine.
Leaving opened low-hydrogen rods in the shop air.

Governing standards: AWS A5.1; AWS A5.5; AWS D1.1 (storage and exposure requirements).

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.

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