high speed steel

• high-speed steel

• enPR: hīʹspēd stēl'

high speed steel (countable and uncountable, plural high speed steels)

1. (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.

• HSS