NASCLA Accredited Commercial General ContractorMetalsMedium
A steel fabricator is preparing to cut structural steel plates using a thermal cutting process that offers high precision and a narrow kerf, suitable for intricate shapes and minimal distortion. Which cutting method is being described?
- ASaw cutting
- BShearing
- COxy-fuel cutting
- DPlasma arc cutting (PAC)
Show answer & explanationAnswer & explanation
Correct answer: D. Plasma arc cutting (PAC)
Plasma arc cutting (PAC) uses an ionized gas stream to cut metal, providing high precision, a narrow kerf (cut width), and faster speeds than oxy-fuel, making it excellent for intricate shapes with less heat distortion. Oxy-fuel is good for thick steel but less precise, shearing is for straight lines, and saw cutting is mechanical.
Why the other options are wrong
- A. Saw cutting is a mechanical process that can be precise but is generally slower and creates more material loss (wider kerf) than plasma for intricate shapes.
- B. Shearing is a mechanical cutting process used for straight cuts on plate and sheet metal, not for intricate shapes.
- C. Oxy-fuel cutting is effective for thick steel but typically has a wider kerf and less precision for intricate shapes compared to plasma.
Thermal Cutting Processes
Methods of cutting metal using heat to melt or vaporize the material, including oxy-fuel, plasma, and laser cutting, chosen based on material, thickness, and required precision.
- Oxy-fuel: Uses oxygen and fuel gas; good for thick carbon steel.
- Plasma Arc Cutting (PAC): Uses ionized gas; high speed, precision, versatile.
- Laser Cutting: Highest precision, minimal heat affect zone, for thinner materials.
Memory trick: Cut Steel: Thermal, Mechanical, Precision Counts.