(metallurgy) A kind of tool steel, invented in the early 20th century, which retains its hardness and temper at high temperatures (at which previous kinds of tool steel would soften), thus allowing cutters made from it to be employed at higher cutting speeds than were previously practical.

Alternative form of high speed steel

plural of high-speed steel

plural of constant speed drive

A type of rail transport that operates significantly faster than traditional rail traffic, using an integrated system of specialized rolling stock and dedicated tracks.

plural of mobile speed bump

(aviation) A type of propeller that rotates at a set rotational velocity, but whose power is set by varying the pitch of the blades.

plural of two-speed crossword

A crossword puzzle allowing the solver to choose from two sets of clues: simple or cryptic.

a bicycle with only one gear ratio