Module 4: Weld Quality & Safety Assessment Quiz

Module: U6M4 - Weld Quality & Safety Duration: 25 minutes Passing Score: 70% Format: Multiple choice and scenario-based

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What is the most basic and commonly used method of weld inspection in a makerspace?

Visual inspection — examining the weld surface for defects with the naked eye and simple tools

Radiographic (X-ray) testing

Ultrasonic testing

Magnetic particle inspection

Submit

Explanation: Visual inspection (VT) is the first and most common inspection method. It can detect surface defects including porosity, undercut, cracks, incomplete fusion, excessive reinforcement, and improper bead profile. It requires only good lighting, a clean weld surface, a magnifier, and trained eyes. More advanced NDT methods are used for critical structural applications.

What is "undercut" in welding, and why is it a serious defect?

A groove melted into the base metal at the toe of the weld that reduces the effective cross-section and creates a stress concentration

A weld bead that is too narrow

A weld that does not penetrate through the material

Excessive filler metal above the surface of the base metal

Submit

Explanation: Undercut is a groove or channel melted into the base metal adjacent to the weld toe. It reduces the base metal's cross-sectional area (weakening it) and creates a sharp notch that concentrates stress. Under cyclic loading, cracks initiate at undercut locations. It is caused by excessive heat, wrong torch angle, or too fast travel speed.

A fillet weld on a T-joint is specified to have ¼" legs. Using a fillet weld gauge, you measure 3/16" legs. Is this weld acceptable?

No — the weld is undersized by 1/16" and does not meet the specified minimum leg size

Yes — 3/16" is close enough to ¼"

It depends on the appearance of the bead

Only if the reinforcement is above average

Submit

Explanation: Weld size specifications are minimum requirements. An undersized weld has reduced load-carrying capacity proportional to its throat area. A ¼" fillet has a theoretical throat of 0.177" (¼ × 0.707). A 3/16" fillet has a throat of only 0.133" — 25% less strength than specified. The weld must be built up to meet the minimum specified size.

What is the purpose of a "bend test" for evaluating weld quality?

To test the ductility and soundness of the weld by bending the specimen until the weld is stretched, revealing internal defects

To measure the hardness of the weld metal

To check if the weld can withstand high temperatures

To verify the chemical composition of the filler metal

Submit

Explanation: A bend test (face bend, root bend, or side bend) forces the weld zone into tension by bending the specimen around a mandrel. If the weld is sound, it will stretch without cracking. Internal defects (lack of fusion, porosity, slag inclusions) that are not visible on the surface will cause the bent specimen to crack or open up, revealing their presence.

Why is it important to maintain a welding logbook documenting parameters and results for each weld?

To track what works, identify recurring problems, demonstrate certification compliance, and enable continuous improvement

To calculate the cost of consumables used

To prove to the instructor that you were present in class

Logbooks are only required in commercial welding shops

Submit

Explanation: A welding log creates an objective record of what parameters produced what results. This enables: learning from past mistakes, replicating successful settings, identifying patterns in defects, documenting certification progress, and providing traceability for projects. It is a professional practice that separates skilled welders from hobbyists.

What is the acceptable limit for weld reinforcement (cap height) on a butt weld according to most codes?

Maximum 1/8" (3mm) above the base metal surface — excessive reinforcement creates stress concentration

There is no limit — more reinforcement means a stronger weld

The reinforcement must be perfectly flush with the surface

Maximum 1/2" above the surface

Submit

Explanation: While reinforcement adds some material, excessive reinforcement creates an abrupt geometry change at the weld toe that concentrates stress — actually WEAKENING the joint under fatigue loading. Most codes (AWS D1.1, ASME) limit reinforcement to ⅛" maximum. For fatigue-sensitive applications, the weld may be ground flush with the base metal.

A student completes a MIG fillet weld. Upon inspection, they notice the weld has good fusion on the horizontal plate but the vertical plate shows a "cold lap" where the weld metal sits on the surface without fusing. What should they do?

Grind out the defective section and re-weld with corrected torch angle directing more heat to the vertical plate

Apply more weld on top of the existing weld

Accept it — the horizontal plate fusion is sufficient

Heat the area with a torch to melt the unfused section

Submit

Explanation: Lack of fusion (cold lap) is a critical defect — the joint has essentially zero strength at that location. Simply welding over it traps the defect. The unfused section must be ground out completely to sound metal, then re-welded with the torch angle adjusted to direct heat into the root of the joint and specifically toward the vertical plate.

What PPE must be worn by ALL personnel within 25 feet of an active welding arc?

At minimum, safety glasses with side shields — or be positioned behind a welding screen

No PPE is needed if they are not the welder

A welding helmet only

Only hearing protection

Submit

Explanation: The welding arc produces UV radiation that can cause arc eye at distances well beyond the immediate welding area. All personnel within 25 feet must either wear safety glasses (minimum protection from reflected UV) or be positioned behind welding screens/curtains. The welder and nearby observers need full welding PPE including welding helmets.

What is the single most effective measure to reduce welding fume exposure?

Local exhaust ventilation (fume extractor) positioned 4-6 inches from the weld zone

Wearing a respirator

Opening a window

Welding faster to reduce exposure time

Submit

Explanation: Local exhaust ventilation captures fumes at the source before they disperse into the welder's breathing zone. Positioned 4-6" from the weld zone (close enough to capture fumes, far enough to not disturb shielding gas), it is the most effective engineering control. Respirators are important but are the last line of defense. General ventilation alone is inadequate for continuous welding.

After welding galvanized steel, a student feels fine but is concerned about zinc fume exposure. When should they expect symptoms if metal fume fever develops?

4-12 hours after exposure — flu-like symptoms including chills, fever, muscle aches, and headache

Immediately during welding

3-5 days after exposure

Metal fume fever has no symptoms

Submit

Explanation: Metal fume fever has a characteristic delayed onset of 4-12 hours. The delay often means welders do not connect their symptoms to the exposure. Symptoms mimic the flu: chills, fever, muscle aches, headache, nausea, and fatigue. They typically resolve within 24-48 hours but are unpleasant and indicate significant fume exposure. Prevention: grind off zinc coating, maximum ventilation, P100+OV respirator.

What is the correct way to store gas cylinders when not in use?

Upright, secured with a chain or strap, valve caps installed, separated by type (fuel from oxidizer by 20 feet or fire wall)

Lying on their side for stability

Near the welding station with the regulator attached

In any position as long as the valve is closed

Submit

Explanation: Compressed gas cylinders must be stored upright (to keep the valve accessible and prevent liquid withdrawal), chained or strapped to a wall or cart (a falling cylinder with a broken valve becomes a rocket), with valve caps installed (protecting the valve from damage), and separated by type (OSHA requires fuel gases and oxidizers be separated by 20 feet or a 5-foot fire-rated wall).

A student wants to weld a crack in a cast iron engine block using MIG welding with ER70S-6 wire. Is this appropriate?

No — cast iron requires specialty filler (nickel-based), preheat, and controlled cooling. Standard MIG wire will crack

Yes — MIG welding works on all ferrous metals

Yes — as long as the crack is ground out first

It depends on the thickness of the casting

Submit

Explanation: Cast iron has 2-4% carbon content — it is extremely crack-sensitive during welding. Standard steel filler (ER70S-6) creates a high-carbon fusion zone that will crack upon cooling. Cast iron welding requires: nickel-based filler rod (ENi-CI or ENiFe-CI), preheat to 400-600°F, slow controlled cooling (peening and insulating blankets), and short stitch welds to manage heat. This is an advanced repair technique.

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Last Updated: 2026-03-19