WELDING ELECTRODE CLASSIFICATIONS

MILD STEEL COATED ELECTRODES

E7018-X

• E - Indicates that this is an electrode
• 70 - Indicates how strong this electrode is when welded. Measured in thousands of pounds per square inch.
• 1 - Indicates in what welding positions it can be used.
• 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 - Flat, Horizontal, Vertical (up), Overhead
• 2 - Flat, Horizontal
• 4 - Flat, Horizontal, Overhead, Vertical (down)
  Flat Position - usually groove welds, fillet welds only if welded like a “V”
  Horizontal - Fillet welds, welds on walls (travel is from side to side).
  Vertical - welds on walls (travel is either up or down).
  Overhead - weld that needs to be done upside 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 - Low Hydrogen, Sodium Medium DCEP
Exxx6 - Low Hydrogen, Potassium Medium AC, DCEP
Exxx7 - Iron Powder, Iron Oxide Medium AC, DCEN
Exxx8 - Low Hydrogen, Iron Powder Medium AC, DCEP
Exxx9 - Iron Oxide, Rutile, Potassium Medium AC, DCEP, DCEN

ADDITIONAL REQUIREMENTS
Suffix Additional Requirement
-1 Increased toughness (impact strength) for E7018 electrodes. Also increased ductility in E7024 electrodes.
-M Meets most military requirements - greater toughness, lower moisture content as received after exposure,
diffusible hydrogen limits for weld metal.

-H4 Indicates the maximum diffusible hydrogen limit measured in millimeters per 100 grams (mL/100g). The 4, 8, and
-H8 16 indicates what the limit is. Example: -H4 = 4mL per 100 grams
-H16

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 was E502 4.6 - 6.0 Cr 0.45 - 0.65 Mo
-B8 was E505 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

Class Min. Tensile Strength Min. Yield Strength
E60xx 62,000 psi 50,000 psi
E70xx 70,000 psi 57,000 psi
E80xx 80,000 psi 67,000 psi
E90xx 90,000 psi 77,000 psi
E100xx 100,000 psi 87,000 psi
E110xx 110,000 psi 95,000 psi
E120xx 120,000 psi 107,000 psi

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