Definition
A thin, fragile lip of metal that forms along the cutting edge of a tool such as a chisel, plane iron, or knife during sharpening. It is the residue pushed off the edge by the abrasive and must be removed by honing or stropping before the tool will cut cleanly.
Plain English
A tiny ragged sliver of metal left hanging on the edge of a blade after you sharpen it. The blade isn't truly sharp until that sliver is removed.
Context Anchor
Seen in aircraft maintenance when metal parts are cut, dressed, repaired, or checked for smooth, safe edges.
Derivation
Called a 'wire' edge because the leftover sliver of metal looks and behaves like a fine length of wire clinging to the edge of the blade.
Why Pilots Care
A tool with a wire edge feels sharp but cuts poorly and dulls almost immediately when used. Mechanics who don't remove it end up with ragged cuts on aircraft materials and waste time re-sharpening tools that were never finished properly.
Intuition Check
A wire edge is not a separate piece of wire. It is a thin, sharp lip of metal left on the edge of the part itself.
Example Sentence 1
After grinding the chisel, the mechanic stropped it on leather to remove the wire edge before trimming the gasket material.
Example Sentence 2
A quick run with a deburring tool removed the wire edge and left the part safe to handle.