If the edge of a chisel quickly becomes dull after each sharpening, it needs:

• A. Hardening and tempering
• B. Regrinding only
• C. Polishing only
• D. Replacing the blade

Answer: (A)

Edge retention in a chisel hinges on the steel’s hardness. If the edge goes dull quickly after sharpening, the edge has likely become too soft or has been annealed, so it can’t hold a sharp edge. Hardening and tempering heat-treats the blade to increase hardness for a longer-lasting edge, while keeping enough toughness to resist chipping. This restores wear resistance so the edge stays sharp longer after subsequent sharpening.

Regrinding only won’t improve hardness; it just removes material and can reveal the underlying soft steel more quickly. Polishing only smooths the surface but doesn’t increase hardness or edge durability. Replacing the blade isn’t necessary if you can restore the edge with proper heat treatment.