WELDING ELECTRODE CLASSIFICATION
SMAW
MILD STEEL COATED ELECTRODES
E7018-X E Indicates that this is an Electrode.
70 Indicates tensile strength. Measured in thousands of pounds per square inch.
1 Indicates welding position.
8 Indicates the coating, penetration, and current type used. (See Classification Table below)
X Indicates that there are more requirements. (See Additional Requirements below)
WELDING POSITIONS
1 All positions (Flat, Horizontal, Vertical (up), Overhead)
2 Flat, Horizontal
4 Flat, Horizontal, Overhead, Vertical (down)
CLASSIFICATION TABLE
Class Electrode Coating Penetration Current Type
Exxx0 Cellulose, Sodium Deep DCEP
Exxx1 Cellulose, Potassium Deep AC, DCEP
Exxx2 Rutile, Sodium Medium AC, DCEN
Exxx3 Rutile, Potassium Light AC, DCEP, DCEN
Exxx4 Rutile, Iron Powder Medium AC, DCEP, DCEN
Exxx5 Basic, Low Hydrogen, Sodium Medium DCEP
Exxx6 Basic, Low Hydrogen, Potassium Medium AC, DCEP
Exxx7 Basic, Iron Powder, Iron Oxide Medium AC, DCEN
Exxx8 Basic, Low Hydrogen, Iron Powder Medium AC, DCEP
Exxx9 Basic, Iron Oxide, Rutile, Potassium Medium AC, DCEP, DCEN
ADDITIONAL REQUIREMENTS
Suffix Additional Requirement
-1 Increased toughness (impact strength).
-M Meets most military requirements - greater toughness, lower moisture content as received after exposure,
diffusible hydrogen limits for weld metal.
-H4, -H8, -H16 Indicates the maximum diffusible hydrogen limit measured in millimeters per 100 grams (mL/100g).
The 4, 8, and 16 indicates what the limit is. Example: -H4 = 4mL per 100 grams
Pierre Dostie
WELDING ELECTRODE CLASSIFICATION
SMAW
LOW ALLOY STEEL COATED ELECTRODES
SUFFIX TABLE
Suffix Steel Alloy Type Suffix Number Description
-A1 Carbon-Molybdenum 0.40 - 0.65 Mo
-B1 Chromium-Molybdenum 0.40 - 0.65 Cr 0.40 - 0.65 Mo
-B2 Chromium-Molybdenum 1.00 - 1.50 Cr 0.40 - 0.65 Mo
-B2L Chromium-Molybdenum Lower Carbon B2
-B3 Chromium-Molybdenum 2.00 - 2.50 Cr 0.90 - 1.20 Mo
-B3L Chromium-Molybdenum Lower Carbon B3
-B4L Chromium-Molybdenum 1.75 - 2.25 Cr 0.40 - 0.65 Mo
-B5 Chromium-Molybdenum 0.40 - 0.60 Cr 1.00 - 1.25 Mo
-B6 4.6 - 6.0 Cr 0.45 - 0.65 Mo
-B8 8.0 - 10.5 Cr 0.8 - 1.2 Mo
-C1 Nickel Steel 2.00 - 2.75 Ni
-C1L Nickel Steel Lower Carbon C1
-C2 Nickel Steel 3.00 - 3.75 Ni
-C2L Nickel Steel Lower Carbon C2
-C3 Nickel Steel 0.80 - 1.10 Ni
-NM Nickel-Molybdenum 0.80 - 1.10 Ni 0.40 - 0.65 Mo
-D1 Manganese-Molybdenum 1.00 - 1.75 Mn 0.25 - 0.45 Mo
-D2 Manganese-Molybdenum 1.65 - 2.00 Mn 0.25 - 0.45 Mo
-D3 Manganese-Molybdenum 1.00 - 1.80 Mn 0.40 - 0.65 Mo
-W Weathering Steel Ni, Cr, Mo, Cu
-G No required chemistry
-M Military grade May have more requirements
CHEMICAL SYMBOLS FOR THE ELEMENTS
C Carbon Most effective hardening element in steel
Mn Manganese Hardening element second to carbon
Si Silicon Deoxidizer, moderate strengthener
P Phosphorus Causes cracking if too high
S Sulfur Aids in machining - Cracking problems like P
Cr Chromium Hardness (low) - corrosion resistance (high)
Ni Nickel Hardening element - better cold toughness
Mo Molybdenum Hardenability - high temp tensile - creep strength
B Boron Very small amounts increase hardness
Cu Copper Corrosion resistance (low) - cracking (high)
Al Aluminum Deoxidizer - improves mechanical properties
Ti Titanium Removes: Oxygen, S, N, and C
N Nitrogen Improves strength - lowers toughness
Cb Columbium Hardness - Improves mechanical properties
V Vanadium Hardness - Improves mechanical properties
Pierre Dostie
