Which of the following is not listed as a welding type?

• A. MIG
• B. TIG
• C. Plasma arc
• D. Water jet cutting

Answer: (D)

Welding processes are methods that join pieces of material by melting and fusing them or bonding them, typically with heat and sometimes shielding gas. MIG and TIG are common arc welding methods—MIG uses a consumable wire electrode with shielding gas, while TIG uses a non‑consumable tungsten electrode with shielding gas for precise welds. Plasma arc welding also fits here as an arc welding method that uses a high-temperature plasma arc to melt and join metal. Water jet cutting, by contrast, is a cutting process that uses a high-pressure jet of water (often with abrasive) to cut through material without fusing it. Because it does not weld, it is not a welding type.