§2.1 · Making the weld
Joining and cutting processes for the CWI
Know each arc process by its shielding, current and filler, read an electrode code like E7018 at a glance, and know how thermal cutting removes metal: that's the joining and cutting area of the CWI. B5.1:2025 gives it the largest minimum of any Part A area, at least 14% (AWS B5.1:2025, Table 8.1, checked October 2026).
- Exam
- CWI
- Clause
- §2.1
- Tags here
- 20
- Part A minimum
- at least 14%
2.1.1One area that used to be two
B5.1:2025 merged two 2013 areas, Welding Processes (12%) and Cutting (2%), into this one. Its capability table expects a welding inspector to know the fundamentals of a long list: SMAW, SAW, OFW, RW, LBW, EBW, GTAW, FCAW, GMAW, PAW, SW, ESW and EGW, plus thermal spraying, soldering, brazing, mechanical cutting and thermal cutting and gouging.
For a fundamentals question you need three things about each process: where the heat comes from, what keeps air off the molten metal, and the main thing that limits it. The five arc processes below are the ones you'll inspect most on structural work. D1.1:2025 even splits its prequalified WPS requirements into separate tables by process.
2.1.2Five arc processes side by side
| Feature | SMAW | GMAW | FCAW | GTAW | SAW |
|---|---|---|---|---|---|
| Electrode | Covered stick | Solid wire | Tubular wire, flux inside | Tungsten | Bare wire |
| Main inspection worry | Damp low-hydrogen rods | Drafts across the nozzle | Wire storage and slag | Tungsten contamination | Flux condition |
| Slag to remove | Yes | No | Yes | No | Yes |
| Filler metal | The electrode | The electrode wire | The electrode wire | Separate rod or wire, or none | The electrode wire |
≠ marks a row where at least one of them differs.
FCAW splits into self-shielded and gas-shielded types that behave differently; see FCAW-S vs FCAW-G.
2.1.3Current, machines and metal transfer
DCEP is electrode positive, the old reverse polarity. DCEN is electrode negative, straight polarity. AC swaps between them every half cycle. Polarity changes how the arc heat divides between the electrode and the work, and the effect is different from one process to the next, so learn it per process.
Machines are classed by output. A constant-current machine holds amperage roughly steady while a welder's hand varies the arc length. A constant-voltage machine holds voltage and lets the wire burn-off settle the arc length.
GMAW moves metal across the arc in short-circuit, globular, spray or pulsed-spray transfer. The modes differ in current, heat and the positions they suit, and the mode affects how sound the weld comes out. How a welder runs those settings on the job is on welding application and control.
Shielding is the weak point of every arc process. A draft across a GMAW nozzle, or a low-hydrogen rod that picked up moisture, usually shows up later as porosity.
Reading an electrode code
Take E7018. E is electrode. 70 is the minimum tensile strength in ksi. 1 means all positions. 8 is the coating: low hydrogen with iron powder. A flux cored wire such as E71T-1 reads the same way: 7 for 70 ksi, 1 for all positions, T for tubular. Carbon steel covered electrodes are classified under AWS A5.1 and carbon steel flux cored wires under A5.20.
There's a Part C catch. D1.1:2025 removed the A5.36 filler classifications, so the filler tables in D1.1:2020 and D1.1:2025 don't list the same designations. AWS lists both editions for Part C (AWS Exam References and Editions Guide, August 2025, checked October 2026), so confirm which one you're on in your confirmation letter.
Thermal cutting and gouging
Oxyfuel cutting preheats steel and burns it away in a jet of oxygen. That works on carbon steel, and it's why the torch doesn't cut stainless or aluminum. Plasma cutting melts the metal with a constricted arc and blows it out, so it handles any conductive metal. Air carbon arc cutting (CAC-A) melts a groove with a carbon electrode while compressed air clears it. It's the usual tool for back gouging and for digging out a rejected weld before a repair.
On a cut edge you check roughness, notches and gouges, dross, and rounded top edges against what the drawing or code allows.
2.1.4Arc, wire and torch
Shielding, polarity, machines, transfer and cutting in one set. On a miss, the remarks tell you which process the wrong option really describes.
0 of 20 tagged · 0 accepted
Tag 01
What is the primary function of flux in submerged arc welding (SAW)?
Remarks on every option
- A Flux doesn't speed cooling; the slag blanket actually slows it. Cooling rate comes from heat input, preheat and plate thickness.
- B Melting rate is driven by amps, volts and travel speed. Flux chemistry can nudge the weld metal, but that's not its main job.
- C Correct: The flux melts into a blanket over the arc, keeps air out and pulls oxides and impurities up into the slag.
- D Heat input is set by amps, volts and travel speed. SAW runs at high heat input anyway; the flux doesn't lower it.
Pick an option. The remarks on all 4 open here.
Tag 02
What is the primary limitation of Submerged Arc Welding (SAW)?
Remarks on every option
- A SAW uses no shielding gas. The granular flux blanket protects the arc, so drafts bother it far less than GMAW.
- B The arc runs buried under flux, so SAW throws next to no spatter. Spatter cleanup is a GMAW/FCAW complaint.
- C High deposition is SAW's selling point. It's the go-to for long seams on thick plate.
- D Correct: Loose flux and a big fluid puddle have to sit on the joint, so SAW is held to the flat position and horizontal fillets.
Pick an option. The remarks on all 4 open here.
Tag 03
In shielded metal arc welding (SMAW), how is the heat necessary for welding generated?
Remarks on every option
- A Resistance heating is how spot and seam welding work. In SMAW the arc does the melting.
- B The coating breaks down into gas and slag to shield the puddle. It doesn't supply the welding heat.
- C Induction heating needs a coil and is used for preheat or brazing. There's no coil in SMAW.
- D Correct: SMAW is an arc process. The arc between the covered electrode and the work melts both.
Pick an option. The remarks on all 4 open here.
Tag 04
What is the primary function of the flux coating in SMAW electrodes?
Remarks on every option
- A Correct: The coating breaks down in the arc into shielding gas and slag, and it adds deoxidizers and sometimes alloy.
- B Travel speed is the welder's call. Some iron-powder coatings raise deposition, but that's not what the coating is for.
- C The slag slows cooling a little, which is the opposite of cooling the pool.
- D Current runs through the core wire. The coating is a poor conductor and isn't there to carry it.
Pick an option. The remarks on all 4 open here.
Tag 05
Which welding process is characterized by using a non-consumable electrode and requires external shielding gas?
Remarks on every option
- A FCAW burns off a consumable tubular wire, and the self-shielded kind needs no gas at all.
- B SMAW burns off a consumable stick and makes its own shielding from the coating. No external gas.
- C Correct: GTAW runs the arc off a tungsten electrode that isn't meant to melt, with inert gas such as argon fed through the torch.
- D SAW feeds a consumable wire and shields with granular flux, not gas.
Pick an option. The remarks on all 4 open here.
Tag 06
Which factor most affects the choice of tungsten electrode diameter in GTAW?
Remarks on every option
- A Correct: Each tungsten size has a current range it carries without overheating or spitting. Size it to your amps.
- B Gas type changes arc heat and cleaning, but you don't size the tungsten off it.
- C Travel speed follows the current and the joint, not the tungsten size.
- D Base metal steers polarity and the tungsten type you pick, but diameter still follows the current.
Pick an option. The remarks on all 4 open here.
Tag 07
In which welding process is the filler metal fed automatically through the welding gun while using external shielding gas?
Remarks on every option
- A SAW is wire-fed too, but it's shielded by granular flux, not gas.
- B In GTAW the filler, if any, goes in separately, by hand or cold-wire feeder. It isn't fed as the electrode through the torch.
- C Correct: GMAW feeds a continuous solid wire electrode through the gun under an external shielding gas.
- D SMAW uses a hand-held covered electrode, and its coating does the shielding.
Pick an option. The remarks on all 4 open here.
Tag 08
In GMAW, what transfer mode is characterized by large droplets transferring across the arc at low frequencies?
Remarks on every option
- A Correct: Globular transfer moves big, irregular drops, often wider than the wire, across the arc a few at a time, with spatter.
- B Pulsed spray drops one small droplet per pulse at a controlled rate, with a low average current.
- C Short-circuit transfer moves metal while the wire touches the puddle. No free-flight drops cross the arc.
- D Spray transfer is a fine stream of small droplets at high frequency, the opposite of big slow drops.
Pick an option. The remarks on all 4 open here.
Tag 09
In GMAW, what transfer mode is most suitable for welding thin materials with minimal heat input?
Remarks on every option
- A Correct: Short-circuit transfer runs at low amps and volts, so it's the low-heat choice for thin sheet and out-of-position work.
- B Globular runs hotter than short-circuit and spatters. It's poor on thin material.
- C Streaming is a high-current form of spray. Too much heat for thin stock.
- D Spray transfer needs high current and puts a lot of heat in. It's for thicker plate, mostly flat and horizontal.
Pick an option. The remarks on all 4 open here.
Tag 10
In GTAW on direct current electrode negative (DCEN), roughly how is the arc heat split?
Remarks on every option
- A An even split is closer to what AC gives you on average. DCEN pushes most of the heat into the work.
- B That's the DCEP split, with most of the heat in the tungsten. It's why DCEP needs a much bigger electrode.
- C Too lopsided. The tungsten still takes close to a third of the heat on DCEN, which is why its size has to suit the current.
- D Correct: On DCEN about 70% of the heat goes into the plate and 30% into the tungsten, so you get deep penetration and can run a smaller tungsten.
Pick an option. The remarks on all 4 open here.
Tag 11
What is the recommended polarity for GMAW of steel using solid wire?
Remarks on every option
- A AC isn't used for solid-wire GMAW on steel. The arc won't run stable as it goes out every half cycle.
- B DCEN with solid steel wire gives an unstable arc and poor transfer. Some self-shielded FCAW wires run DCEN; solid GMAW doesn't.
- C Correct: Solid-wire GMAW on steel runs DCEP (reverse polarity) for a stable arc and good penetration.
- D Variable polarity shows up in some aluminum and plasma work. It isn't the standard setup for steel GMAW.
Pick an option. The remarks on all 4 open here.
Tag 12
What type of current is typically used for GTAW of aluminum?
Remarks on every option
- A Correct: AC cleans the oxide on the electrode-positive half and gives penetration on the electrode-negative half.
- B Pulsed DC on DCEN still gives no cleaning action, so the aluminum oxide stays put.
- C DCEN gives penetration but no oxide cleaning, so it isn't the usual choice for aluminum. It's what you run on steel and stainless.
- D DCEP cleans well but puts most of the heat into the tungsten, which overheats unless it's very big. That's why AC is used.
Pick an option. The remarks on all 4 open here.
Tag 13
In gas tungsten arc welding (GTAW), which type of power source is typically used to maintain the stability and precision of the arc?
Remarks on every option
- A Correct: GTAW uses a constant-current (drooping) machine, so small changes in arc length barely change the amps.
- B Inverter describes how the machine is built, not its output type. An inverter can be built for CC or CV.
- C Not a standard class for GTAW machines. They're classed constant current or constant voltage.
- D Constant voltage goes with wire-feed processes like GMAW and FCAW, where the arc self-regulates on wire burn-off.
Pick an option. The remarks on all 4 open here.
Tag 14
What type of power source is most appropriate for automated GMAW operations in a high-production setting?
Remarks on every option
- A Constant current is for SMAW and GTAW. Put a wire feeder on CC and the arc length wanders.
- B AC is a type of current, not an output characteristic, and steel GMAW runs DC anyway.
- C Not the standard term. GMAW machines are classed constant voltage (constant potential).
- D Correct: GMAW runs on constant voltage. The arc corrects its own length as the wire burns off, which suits automated, high-production work.
Pick an option. The remarks on all 4 open here.
Tag 15
What is the primary advantage of using Plasma Arc Welding (PAW) over GTAW?
Remarks on every option
- A PAW costs more, not less. It adds a constricting nozzle, orifice gas and a pilot arc circuit to a GTAW-style setup.
- B Correct: The constricted plasma arc is narrow and concentrated, so PAW gets deeper penetration (even keyhole mode) and faster travel than GTAW.
- C PAW needs gas twice over: orifice gas to form the plasma and shielding gas around it.
- D PAW has more settings than GTAW, such as orifice gas flow and electrode setback, so it isn't simpler to run.
Pick an option. The remarks on all 4 open here.
Tag 16
What is the primary advantage of using Electroslag Welding (ESW)?
Remarks on every option
- A ESW only runs vertical or close to it. Shoes hold the molten slag and pool in as the weld climbs the joint.
- B Correct: ESW fills a thick square-edge joint in one vertical pass. That's the whole point on heavy plate.
- C Opposite. ESW has very high heat input and a wide, coarse-grained heat-affected zone.
- D ESW needs dams or copper shoes, often water-cooled, plus a starting sump. Setup is heavy, not quick.
Pick an option. The remarks on all 4 open here.
Tag 17
Which feature indicates proper cutting speed in oxy-fuel cutting?
Remarks on every option
- A A rounded or melted top edge means the preheat flame is too close or too hot, or travel is too slow.
- B Correct: At the right speed the drag lines run nearly straight up and down the cut face. Lines that lean back mean you're going too fast.
- C Drag lines that lean back and lag mean travel is too fast; the bottom of the cut trails the top.
- D A smooth face is good, but on its own it doesn't tell you the speed. The drag line pattern does.
Pick an option. The remarks on all 4 open here.
Tag 18
Which cutting process provides the narrowest kerf width?
Remarks on every option
- A Plasma cuts fast with a narrow kerf, but wider than a laser on comparable stock.
- B Oxy-fuel leaves the widest kerf of these. The oxygen stream burns out a slot.
- C Water jet kerf is tight, but the jet is still wider than a focused laser beam.
- D Correct: A focused laser beam leaves the narrowest kerf of these processes.
Pick an option. The remarks on all 4 open here.
Tag 19
What cutting process should be selected for a 4-inch thick carbon steel plate?
Remarks on every option
- A Laser is for thin-to-medium plate. Four inches of carbon steel is well past what it cuts economically.
- B Correct: Oxyfuel cuts carbon steel by burning it in an oxygen stream, and it handles 4 in plate well and cheaply.
- C Plasma is fast on thinner plate, but 4 in is beyond what most shop plasma systems cut well.
- D Water jet can cut thick steel, but it's very slow at 4 in. It's picked when heat must be avoided, not for routine thick carbon steel.
Pick an option. The remarks on all 4 open here.
Tag 20
Which condition requires immediate shutdown of an oxyfuel cutting system?
Remarks on every option
- A Correct: A flashback is the flame burning back into the torch or hoses. Shut the torch valves right away and find the cause before relighting.
- B Slight discoloration of the tip or the work is normal heating. No shutdown needed.
- C A backfire is a loud pop that can put the flame out. Check the tip and settings and relight; it's not the sustained burn-back of a flashback.
- D Minor tip wear means clean or replace the tip when you get a chance. Not an emergency.
Pick an option. The remarks on all 4 open here.
2.1.5From the shop floor to Part A
Do I have to know processes I never run, like electroslag or electron beam?
At the fundamentals level, yes. B5.1:2025 lists ESW, EGW, EBW, LBW, resistance welding and stud welding next to the everyday arc processes. For each one, know how it makes heat, how it's shielded and what limits it.
Do I need the whole AWS filler metal classification system?
No. Learn to read the common codes, know which A5 specification covers which family, and if you're taking Part C on D1.1, know that the 2025 edition dropped the A5.36 classifications.
Is self-shielded flux cored the same process as gas-shielded?
Same letters, different behavior. One makes all of its shielding from the core; the other needs gas from a cylinder too. FCAW-S vs FCAW-G covers what changes for an inspector.
Where does heat input come in?
The process sets the range of amps, volts and travel speed you can run, and those three set heat input. The formula is on welding calculations, and what heat does to the steel is on heat control and metallurgy.
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