🔍 Key Concepts

• weld joint terminology such as root, groove, and weldment • difference between joint preparation dimensions (before welding) and dimensions of the finished weld • how the root opening relates to the two plates being joined in a V‑groove weld

💭 Think About

• Look at where the dimension labeled 0 to 1/8" is taken on the illustration: is it measured between the plates before weld metal is added, or on the finished weld bead? • Ask yourself: does "root opening" describe metal thickness, weld penetration, or the gap between pieces to be welded? • Compare the idea of penetration depth with the physical gap that must be left so the weld can fully fuse the root area.

✅ Before You Answer

• Identify exactly what two surfaces the root opening dimension arrowheads are touching in the sketch. • Confirm whether the dimension refers to the base metal joint before welding or the deposited weld metal afterward. • Make sure your choice uses the term that best matches a gap or spacing at the root of the V, not the size of the completed weld bead.