Click image to open full size
Welding Processes Comparison Cheat Sheet
A printable reference covering SMAW, GMAW, GTAW, FCAW, weld quality, safety, heat input, and process selection for grades 9-12.
Related Tools
Related Worksheets
This cheat sheet compares common welding processes used in engineering, manufacturing, construction, and repair work. Students need it to choose the right process for a material, joint, position, and production goal. It also helps connect welding vocabulary to real shop decisions about cost, speed, quality, and safety. The core processes include SMAW, GMAW, GTAW, and FCAW, each with different equipment, shielding, skill level, and weld quality. Important comparison factors include heat input, penetration, deposition rate, travel speed, and shielding method. Good weld selection balances strength, appearance, productivity, material thickness, and the environment where welding occurs.
Key Facts
- SMAW, or stick welding, uses a flux-coated consumable electrode that creates shielding gas and slag as it burns.
- GMAW, or MIG welding, uses a continuously fed wire electrode and an external shielding gas such as argon, carbon dioxide, or a mixture.
- GTAW, or TIG welding, uses a nonconsumable tungsten electrode and separate filler metal when needed, producing precise and clean welds.
- FCAW uses a tubular wire filled with flux and may be self-shielded or used with external shielding gas.
- Heat input can be estimated by Heat input = Voltage x Current x 60 / Travel speed, where travel speed is in length per minute.
- Deposition rate is the amount of filler metal added per time, usually measured in lb/hr or kg/hr.
- Higher travel speed usually lowers heat input and can reduce penetration if voltage and current stay the same.
- Outdoor welding often favors SMAW or self-shielded FCAW because wind can blow away shielding gas in GMAW and GTAW.
Vocabulary
- SMAW
- Shielded metal arc welding is a process that uses a flux-coated stick electrode to create the arc, filler metal, and shielding.
- GMAW
- Gas metal arc welding is a process that uses a continuous wire electrode and external shielding gas.
- GTAW
- Gas tungsten arc welding is a process that uses a tungsten electrode to create a precise arc with optional filler metal.
- FCAW
- Flux-cored arc welding is a process that uses a hollow wire electrode containing flux to protect and shape the weld.
- Shielding
- Shielding is the protection of molten weld metal from oxygen, nitrogen, and moisture in the air.
- Penetration
- Penetration is the depth that the weld melts into the base metal.
Common Mistakes to Avoid
- Choosing GMAW for windy outdoor work without protection is a mistake because the shielding gas can be blown away and cause porosity.
- Assuming TIG is always the best welding process is wrong because GTAW is clean and precise but often slower and more expensive than other methods.
- Using too much heat input is a mistake because it can cause warping, burn-through, a wide heat-affected zone, and weaker properties in some metals.
- Ignoring base metal thickness is wrong because thin sheet often needs lower heat and control, while thick plate may require deeper penetration and multiple passes.
- Comparing welding processes only by speed is a mistake because strength, appearance, position, material type, safety, and environment also affect the best choice.
Practice Questions
- 1 A weld is made at 24 V and 180 A with a travel speed of 12 in/min. Using Heat input = Voltage x Current x 60 / Travel speed, what is the heat input in J/in?
- 2 A welder deposits 6 lb of filler metal in 3 hours. What is the deposition rate in lb/hr?
- 3 Which process is usually better for a clean, precise weld on thin stainless steel: GTAW or SMAW? Explain the reason.
- 4 A repair must be made outside on a windy construction site. Explain why SMAW or self-shielded FCAW may be a better choice than GMAW.