Definition
A family of alloy steels containing tungsten, chromium, vanadium, molybdenum, or cobalt that retain their hardness and cutting edge at the high temperatures generated during machining. High-speed steel is commonly used for drill bits, taps, reamers, and other cutting tools used in aircraft maintenance work.
Plain English
A tough type of steel used to make cutting tools like drill bits. It stays hard and sharp even when it gets hot from cutting through metal, which is why it works well on aircraft parts.
Context Anchor
Seen in aviation maintenance when selecting drill bits, taps, dies, and other cutting tools for metal work.
Derivation
Named for its ability to cut at high speeds. Earlier carbon-steel tools lost their hardness when they got hot and had to be run slowly. The new alloy could keep cutting at much higher speeds without softening, so it was simply called 'high-speed' steel.
Why Pilots Care
A mechanic choosing the wrong tool material can ruin a hole, dull a tool quickly, or damage expensive aircraft hardware. Knowing why high-speed steel is used helps a technician pick the right drill bit or tap for the job.
Intuition Check
Do not read “high-speed steel” as steel that is moving fast. It means steel made for cutting tools that can work at higher cutting speeds and temperatures without losing hardness.
Example Sentence 1
He selected a high-speed steel drill bit to make the hole in the aluminum bracket.
Example Sentence 2
High-speed steel cutters held their edge through repeated passes when shaping the steel engine mount brackets.