The two main cutting-tool materials. The choice sets your speeds, tool life and cost.
HSS (High-Speed Steel)
Tougher and cheaper; tolerates interrupted cuts, less-rigid setups and manual machines — but runs at lower cutting speeds. Common for drills, taps and general tooling.
Carbide
Much harder and heat-resistant, so it runs 2–4× faster and lasts longer, especially in steel — but it's more brittle and needs rigid setups. The standard for production, usually as coated inserts.
Bottom line
Carbide for speed, tool life and production on rigid CNC machines; HSS for toughness, interrupted cuts, hard-to-reach setups and lower cost. Most shops use carbide for the bulk of work and keep HSS for specific jobs.
