SMAW Welding: 26V / 120A
Heat input at travel speeds 100–300 mm/min (efficiency η=0.8)
SMAW at 26 V and 120 A is a workhorse parameter set used across structural fabrication, pipe welding, and general repair work on carbon and low-alloy steels. At this electrical input the arc transfers enough energy to fuse plate from about 3 mm up to roughly 12 mm in single-pass work, with thicker sections handled in multiple passes following a qualified WPS. The voltage value controls arc length and bead width while the current value governs deposition rate and penetration; together they define a stable operating envelope that experienced welders can read from puddle behavior alone. Always match the wire diameter and shielding gas to the parameter set called out in your Procedure Qualification Record.
SMAW (Shielded Metal Arc Welding), commonly called stick welding, uses a consumable coated electrode. The flux coating generates shielding gas and slag to protect the weld pool. Highly portable and versatile, SMAW is used in maintenance, repair, pipeline, and structural applications where access is limited.
At 26 V and 120 A, the electrical input power is 3120 W. Voltage primarily controls arc length and bead profile — higher voltage widens and flattens the bead — while current drives deposition rate and penetration depth. Exceeding the rated current for a given wire diameter increases the risk of burn-through on thin sections and premature contact-tip wear.
Heat input directly affects the weld metallurgy. Lower heat input preserves heat-sensitive alloys and reduces distortion; higher heat input improves fusion on thick sections but may coarsen grain structure and reduce toughness. Always verify that heat input falls within the Procedure Qualification Record (PQR) limits for the base material. For carbon steel, heat input above 3.5 kJ/mm may require post-weld heat treatment (PWHT) to restore toughness in the heat-affected zone (HAZ).
Welding Specification
| Process | SMAW |
| Voltage | 26 V |
| Current | 120 A |
| Process Efficiency | η = 0.8 |
Heat Input by Travel Speed
| Travel Speed (mm/min) | Heat Input Q (kJ/mm) |
|---|---|
| 100 | 1.498 |
| 150 | 0.998 |
| 200 | 0.749 |
| 250 | 0.599 |
| 300 | 0.499 |
Amperage Range Notes
Low-amperage welding (under 150 A) is the territory of thin-gauge sheet metal work — typically material under 3 mm where heat input must be tightly controlled to prevent burn-through, blow-out, and excessive distortion. Use small-diameter wire or rod (0.030 inch / 0.8 mm for GMAW, 3/32 inch / 2.4 mm for SMAW), short arc length, and a stitch or skip-weld pattern that lets the base metal cool between passes. Root passes on heavy joints also live in this range. Lower current allows precise puddle control for tube-to-sheet joints, automotive body repair, and HVAC ductwork fabrication.
Typical Use Cases
SMAW at 26 V / 120 A is suited to general-purpose carbon steel fabrication in the flat or horizontal position. Verify wire diameter and shielding gas composition against your weld procedure specification (WPS) before production runs.
Setup Checklist
Confirm wire feed speed matches the target current range. Set gas flow rate to 15–25 CFH for solid wire GMAW, or follow the flux manufacturer's instructions for FCAW. Inspect contact tips and liners for wear before welding. Preheat thick sections (> 25 mm) to reduce hydrogen cracking risk.