Base metal strength
Match mechanical properties. Mild steel fabrication typically uses E-6013 or E-7018 class electrodes. Low-alloy and high-tensile structures need E-7018 or grades specified on the drawing.
Technical guide
Welding process & procedure
Hands-on SMAW guidance for Indian fabrication shops, structural yards, maintenance teams, and MIDC manufacturing units using Bharatweld electrodes.
Shielded metal arc welding (SMAW) on the shop floor
Manual arc welding with coated electrodes remains the backbone of Indian industry - from gate and grill fabricators in tier-2 towns to heavy structural contractors and in-plant maintenance crews. A good weld is rarely about one setting alone; it is the balance of rod size, current, arc length, travel speed, and rod angle for the joint in front of you.
This guide translates core welding procedure principles into practical steps you can apply on transformer sets, diesel welders, and modern inverters found across construction sites and fabrication bays.
- Clean rust, paint, and moisture from the joint - especially during monsoon work
- Dry low-hydrogen rods (E-7018) when required; store electrodes per manufacturer advice
- Use the right Bharatweld grade for base metal - see our industries page
Core technique
Five essentials of a proper welding procedure
Master these before chasing advanced joints. Each variable affects the molten pool, penetration, and final bead profile.
How to judge weld quality while you work
Listen for a steady, controlled sizzling arc - not loud cracking or a dull drag. Watch the molten pool: it should stay slightly ahead of the arc and flow evenly into the cooling bead behind you. After slag removal, ripples should be regular, the face smooth, with no overlap onto base metal and no undercut along the toes.
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Correct electrode size
Rod diameter controls heat input and how much metal you deposit per pass. Choose size based on joint type, plate thickness, welding position, and whether you need root penetration or a cosmetic cap.
What to weigh on Indian jobs
- Thin sheet & grills - 2.5 mm or 3.15 mm E-6013 for smooth finish and easy slag peel
- Medium frames & channels - 3.15 mm for general fabrication; step up only if fusion is lacking
- Heavy columns & thick plate - 4 mm E-7018 with low-hydrogen handling for structural integrity
- Vertical or overhead - often one size smaller to control the pool on long shop runs
Tip: A rod that is too large overheats thin MS sheet; too small on thick plate causes lack of fusion and repeated passes.
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Correct current (amperage)
Current must match rod size and position. Manufacturer tables on the box are your starting point - then fine-tune by ear and by how the pool behaves on your actual machine and cable length.
Signs on the job
- Too high - electrode melts rapidly, pool spreads wide and irregular, undercut risk on edges
- Too low - stubbing or sticking, narrow piled bead, cold-looking ripples, weak fusion
- Just right - smooth deposition, pool visible and controlled, steady sound
Site note: Long leads and generator welders on remote construction jobs often need slightly higher settings - adjust arc length first before maxing amperage.
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Correct arc length & voltage
Arc length is the gap between the rod tip and the pool. On most SMAW work it should stay close to the metal core diameter - not the full coated size of the electrode.
Effects welders notice daily
- Long arc / high voltage feel - metal transfers in large globules, spatter on nearby work, wide bead with shallow fusion
- Short arc - rod sticks, bead rides high, ripples look cramped, porosity risk if you pause
- Balanced arc - crisp transfer, minimal spatter, bead sits flush with parent metal
Outdoors: Wind and long arcs increase spatter and porosity - use screens where possible on critical structural work.
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Correct travel speed
Travel speed is how fast you move along the joint. It decides how long heat stays in the metal and whether slag and gas can escape before the pool freezes.
Practical guidance
- Too fast - narrow bead, sharp ripples, trapped gas, lack of sidewall fusion on fillets
- Too slow - high crown, wide bead, heat build-up, burn-through on thin plate
- Steady pace - pool size stays consistent; on long runs (railings, conveyor frames) maintain rhythm
Fabrication bays: Mark stop/start points on repeat jobs so every welder matches production speed and appearance.
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Correct electrode angle
Angle matters most on fillet welds, lap joints, and deep groove passes where you must direct heat into both members without cutting away the vertical or horizontal toe.
Fillet welding rule
- Hold the rod so it bisects the angle between the two plates and stays perpendicular to the weld direction
- If the vertical leg shows undercut, lower the angle and point more heat toward that member
- On open grooves, use stringer or slight weave per WPS - avoid excessive weaving on E-7018 structural passes
Common in India: Stair stringers, platform brackets, and MS gate frames - practice 6 mm fillets flat before moving to vertical-up production work.
Electrode selection
Eight factors when choosing arc welding electrodes
Before you open a new box on site, match the rod to metal, position, power supply, and the service the weld will see.
Base metal composition
Know what you are joining. Plain carbon steel accepts most rutile or low-hydrogen rods. Alloy or stainless grades need a matching composition - wrong chemistry leads to crack-sensitive welds.
Bharatweld: E-308L for 304/308 stainless in food & chemical plants
Welding position
Flat, horizontal, vertical-up, and overhead each demand electrodes designed for that position. Using a flat-only rod vertically often gives excessive drip and a weak profile.
Site: Overhead maintenance in plants - practice on scrap before production overhead passes
Welding current available
Some rods run best on DC; others on AC site welders. Check polarity (DCEP / DCEN) on the machine label and the electrode packet - incorrect polarity causes unstable arc and poor penetration.
Tip: Many Indian workshops still use AC transformers - choose electrodes rated for your supply
Joint design & fit-up
Root gaps and bevels dictate penetration needs. Tight square joints may need a digging arc; wide gaps or thin sheet need a softer, lower-penetration character to avoid blow-through.
Fabrication: Poor fit-up on truss nodes - fix gap with tacking, not by flooding one slow pass
Thickness & shape
Thick sections and restrained assemblies build stress. Prefer electrodes with higher ductility and low-hydrogen practice on heavy plate and complicated frames to reduce cracking.
Heavy industry: E-7018 with controlled handling on mining and structural plate work
Service conditions
Low temperature, impact loading, vibration, or corrosive environments may require specific grades or low-hydrogen processes. Always follow project WPS or client specification when provided.
Examples: Outdoor gates (weather) | Pressure-boundary work (spec-controlled) | Stainless tanks (E-308L)
Production efficiency
Flat-position bulk work may justify larger diameters or high-deposition types. Mixed-position fabrication shops often keep a core range (2.5, 3.15, 4 mm) of proven grades to reduce changeover.
Also consider: Cutting electrodes for gouging | Manganese for hardfacing wear areas
Need the right Bharatweld grade?
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