Stick electrodes
Reading an AWS A5.1 / A5.5 stick electrode code
| Part | Example E7018 | Meaning |
|---|---|---|
| E | E | Electrode for arc welding |
| First 2 (or 3) digits | 70 | Minimum tensile strength in ksi: 60 = 60 000 psi (414 MPa), 70 = 70 000 psi (483 MPa) |
| Next digit | 1 | Welding position: 1 = all positions, 2 = flat and horizontal fillet only, 4 = all including vertical-down |
| Last two digits | 18 | Coating type and current (see table) |
Coating and current (last two digits)
| Ending | Coating | Current | Character |
|---|---|---|---|
| 10 | High cellulose, sodium | DC+ | Deep, forceful arc; root runs and pipe |
| 11 | High cellulose, potassium | AC or DC+ | Like 10 but runs on AC sets |
| 12 | High titania (rutile), sodium | AC or DC− | Medium penetration, bridges poor fit-up |
| 13 | High titania (rutile), potassium | AC or DC± | Soft, easy arc; neat finish on light work |
| 14 | Rutile + iron powder | AC or DC± | Faster deposition than 13 |
| 15 | Low hydrogen, sodium | DC+ | Crack-resistant welds |
| 16 | Low hydrogen, potassium | AC or DC+ | Crack-resistant welds on AC |
| 18 | Low hydrogen, potassium + iron powder | AC or DC+ | Structural and pressure work; keep rods dry |
| 20 | High iron oxide | AC or DC± | Flat and horizontal fillets |
| 24 | Rutile + iron powder (heavy) | AC or DC± | Fast flat fillets |
| 27 | Iron oxide + iron powder | AC or DC± | High deposition, flat position |
| 28 | Low hydrogen + iron powder (heavy) | AC or DC+ | Fast low-hydrogen flat fillets |
Choosing and setting up
Which rod for which job
| Electrode | Best for | Watch out for |
|---|---|---|
| E6010 / E6011 | Root passes, rusty or dirty steel, pipe | Rough finish; needs skill |
| E6013 | General light fabrication, sheet, gates, repairs | Not for crack-sensitive or high-strength steel |
| E7018 | Structural steel, heavier sections, anything load-bearing | Must be kept dry (rod oven); hard to strike when damp |
| E7024 | Long flat or horizontal fillets fast | Flat and horizontal only |
| E308L-16 | 304 / 304L stainless | Use E316L for 316 / marine |
| E309L-16 | Joining stainless to mild steel | - |
| ENiFe-CI | Cast iron repairs, cast iron to steel | Weld short runs, peen, cool slowly |
Stick welding current (guide)
| Rod dia. mm | E6013 amps | E7018 amps | Typical plate mm |
|---|---|---|---|
| 2.0 | 40 - 70 | - | 1.5 - 3 |
| 2.5 | 60 - 95 | 70 - 100 | 2 - 5 |
| 3.2 | 90 - 130 | 100 - 140 | 3 - 8 |
| 4.0 | 120 - 180 | 140 - 190 | 6 - 12 |
| 5.0 | 160 - 230 | 190 - 260 | 10 + |
MIG wire size (guide)
| Wire dia. mm | Amps | Steel thickness mm |
|---|---|---|
| 0.6 | 30 - 90 | 0.6 - 2 |
| 0.8 | 40 - 150 | 0.8 - 4 |
| 0.9 | 50 - 180 | 1 - 5 |
| 1.0 | 70 - 220 | 2 - 8 |
| 1.2 | 120 - 300 | 4 + |
Rule of thumb for stick welding: about 40 A per mm of rod diameter. Start in the middle of the range and adjust: too cold leaves a tall, narrow bead that sits on top; too hot undercuts and spatters.
Gas, tungsten and safety
Shielding gas
| Process / metal | Shielding gas | Notes |
|---|---|---|
| MIG - mild steel | Argon + 15-20% CO2 | General purpose, low spatter |
| MIG - mild steel | 100% CO2 | Deep penetration, cheaper, more spatter |
| MIG - stainless | Argon + 2% CO2 (or tri-mix) | Avoid high CO2 |
| MIG - aluminium | 100% argon | Use a spool gun or Teflon liner |
| TIG - all metals | 100% argon | Typical flow 8 - 15 L/min |
| Flux-cored (gasless) | None | Good outdoors in wind |
TIG tungsten electrodes
| Tungsten (ISO 6848) | Tip colour | Use |
|---|---|---|
| WP pure | Green | AC aluminium on older transformer sets |
| WC20 2% ceriated | Grey | AC/DC, good low-amp starts |
| WL15 1.5% lanthanated | Gold | AC/DC all-rounder |
| WL20 2% lanthanated | Blue | AC/DC all-rounder |
| WT20 2% thoriated | Red | DC steel and stainless (slightly radioactive: extract grinding dust) |
| WZ8 0.8% zirconiated | White | AC aluminium, holds a balled tip |
Lens shade (guide)
| Process | Current | Filter shade |
|---|---|---|
| Stick (MMA) | 40 - 80 A | 10 |
| 80 - 175 A | 11 | |
| 175 - 300 A | 12 | |
| over 300 A | 13 | |
| MIG / MAG | up to 100 A | 10 |
| 100 - 175 A | 11 | |
| 175 - 300 A | 12 | |
| TIG | up to 50 A | 10 |
| 50 - 150 A | 11 | |
| 150 - 250 A | 12 | |
| Gas welding / brazing | - | 4 - 6 |
Start with a darker lens and go lighter only until the weld pool is clearly visible. Always weld with ventilation or extraction, especially on galvanised, painted or stainless material.
Weld symbols - the basics
| Symbol | Means |
|---|---|
| Triangle | Fillet weld; the number in front is the leg size (AWS) or throat a / leg z (ISO 2553) |
| Two parallel lines | Square butt weld |
| V | Single-V butt weld |
| Half V (one vertical side) | Single-bevel butt weld |
| U / J shape | U or J groove |
| Circle on the arrow junction | Weld all round |
| Flag | Field (site) weld |
| Symbol below the line (AWS) | Weld on the arrow side; above the line = other side |
| Dashed line (ISO) | Symbol on the solid line = arrow side; on the dashed line = other side |