Prepare for your Welding Certification exam with these practice questions and answers. This guide covers MIG/GMAW, TIG/GTAW, stick/SMAW welding, safety procedures, and weld inspection techniques.
Q: What power source is required to perform GMAW (MIG) welding?
Answer: DC constant potential – voltage
Q: What types of metal transfer are possible with GMAW (MIG) process when welding?
Answer: Short circuit, Globular, and Spray Transfer
Q: List two advantages and two disadvantages of GMAW (MIG) welding.
Answer: Advantages: higher production rate, faster welding speedDisadvantages: less portable, requires more operator skills and techniques for welding and equipment setup
Q: What is the main function of the contact tip in a MIG welding gun?
Answer: Relay welding currents from the power source to the filler metal (guide the filler metal to work piece)
Q: Which diameters of wire sizes are most commonly used in short circuit metal transfer when MIG circuit metal transfer when MIG welding?
Answer: 0.023, 0.030, 0.035, 0.045
Q: What current and polarity is most commonly used when GMAW wedling?
Answer: DC – direct current reverse polarity
Q: What type of current is not used when GMAW welding?
Answer: Alternating Current (AC)
Q: What does the term MIG stand for?
Answer: Metal Inert Gas
Q: What does the term GMAW stand for?
Answer: Gas Metal Arc Welding
Q: What is the purpose of a shielding gas when GMAW?
Answer: 1) To prevent contamination of the weld metal2) To influence the welding arc and effects the width and depth of weld penetration and amount of spatter
Q: On a GMAW welding setup what causes the amperage to increase or decrease?
Answer: The dial on the wire feed mechanism. High amperage, more wire. Low amperage, less wire speed.
Q: The constant potential welding machine has a voltage range of _____ to _____ volts?
Answer: 15-48 V
Q: To perform short circuit metal transfer when GMAW welding a voltage range of what required?
Answer: 15-22 V
Q: What type of metal transfer when GMAW welding requires higher current voltages?
Answer: Spray transfer
Q: Insufficient current transfer between power source and filler wire is a direct result of what when GMAW welding?
Answer: A badly worn contact tip on welding gun
Q: What part of the MIG welding gun is the contact tip fastened to?
Answer: Tip adapter (gas diffuser)
Q: When GMAW welding, the travel angle of the welding gun varies from _____ to _____ and should never exceed _____.
Answer: Varies from 5-15 degrees.Shouldn’t exceed 20 degrees.
Q: What does the contact tip adapter or (gas diffuser) on a MIG welding gun do?
Answer: Relays electricity to contact tip and diffuses gas flow to weld puddle
Q: What does the gas nozzle on a MIG welding gun do?
Answer: Directs gas flow from gas diffuser to weld puddle and prevent contact tip from arcing out on the work piece
Q: When MIG welding, the flow meter on your botle gauge should be set at approximately _____ to _____ cubic feet per hour.
Answer: 20 to 25 cubic feet per hour.Maximum flow 35 cubic feet per hour, but can cause turbulence.
Q: Spatter buildup on the gas nozzle and wind or drafts in the shop have a direct effect on what?
Answer: Shielding gas flow and turbulence. NOTE: may cause porosity in your weld
Q: In regards to welding wire filler metals used in GMAW, what do the letters and numbers ER70S3 refer to?
Answer: ER – stands for GMAW electrode70 – 70 000 psi tensile strengthS – stands for solid wire3 – designates the chemical composition of the wire and the mechanical properties of the deposited metal6 – added oxidizers for welding on rust oxides and other surface impurities
Q: Nozzle insulators provide protection from electrical contact and also direct gas flow. Why is it important to frequently check their condition?
Answer: Due to the high temperature they are susepted to the material tends to burn out. A short can occur in nozzle, also spatter tend to build up and can effect shielding gas flow.
Q: When welding thin gauge materials such as 22 gauge, what would be the ideal diameter wire size to use?
Answer: 0.023
Q: Why is it important to properly adjust the wire feed drive rollers?
Answer: A constant and regular feed rate is of the utmost importance in controlling the molten weld puddle and the deposition rate of the filler metal
Q: When changing the wire in your MIG welding machine from one size of wire to another, what three things should the welder check first?
Answer: 1) Rollers are compatible with the wire2) Liner is clean and compatible3) correct size contact tip
Q: Why is periodic maintenance of the wire liners, cleaning, and inspection for kinks important?
Answer: To ensure a smooth and constant wire feed rate
Q: When MIG welding what is the difference between a pushing and pulling technique of the hand gun?
Answer: Pushing – less penetration and a wider weld beadPulling or Dragging – deep penetration and higher narrower weld bead
Q: What should a welder never do while feeding the wire through the liner and contact tip?
Answer: Never look into the contact tip while the wire is moving and never hold your finger or thumb over the nozzle
Q: What range of lens shades are appropriate for an experienced GMAW welder to use in their welding helmet?
Answer: #9 – #11
Q: What is an appropriate electrode extension or stick out distance for the wire to protrude from the contact tip when a circuit transfer method is used?
Answer: 1/4″ to 1/2″ average
Q: What does the duty cycle refer to on a MIG welding machine?
Answer: The duty cycle is the percentage of time a welding machine can be used continuously: 60% duty cycle = 6 minute out of 10 minute of operation