W210 is a European water-hardening tool steel, carried in Germany under DIN designation 100V1 and Werkstoffnummer 1.2833. It sits in the same family as AISI W2: a plain high-carbon steel (around 1% carbon) with a small vanadium addition and essentially no chromium, molybdenum, or nickel. That lean alloy content is the point of a water-hardening grade — there is nothing in the chemistry to slow the quench or push hardenability deep into the section, so W210 forms a thin, very hard case with a comparatively soft, tough core when it is water quenched from the austenitizing temperature. The vanadium addition is small but functional: it forms fine carbides that pin grain growth during hardening, giving W210 a finer as-quenched grain structure and better edge stability than a plain carbon water-hardening steel with no vanadium at all.

That combination — a glass-hard working surface over a resilient core — is exactly what water-hardening tool steels are chosen for: cutting edges and wear surfaces that need to be very hard (W210 quenches to around 65 HRC) but that also benefit from a core that can absorb shock without the whole section becoming brittle. Typical uses include tap drills, broaching tools, cold-heading dies, stone-working tools, and other cold-work tooling where a hard, shallow case is an advantage rather than a liability. Because hardenability is shallow by design, W210 is not the right choice for heavy sections or tooling that needs to be hard all the way through — that is where the alloyed cold-work and oil-hardening grades take over.

Chromium, molybdenum, and nickel are not intentionally added — the low alloy content is what gives this grade its shallow, water-hardening response.

In the annealed condition W210 machines much like a plain medium-to-high carbon steel, because that is essentially what it is. There is no carbide network to fight through the way there is in a chromium-rich cold-work grade like D2, so cutting forces stay moderate and standard carbide tooling handles it without difficulty. The main variable shops need to watch is condition: W210 is almost always machined soft (annealed, typically in the 190-220 HB range) and then water-quenched to final hardness afterward, so any machining done post-hardening is grinding work, not turning or milling — the as-quenched 65 HRC surface is far too hard and too shallow-cased for conventional cutting tools.

Because the carbon content is on the high side for a plain steel, chip control is generally good and edge wear tends to be gradual rather than sudden, provided the material hasn't been left in a partially spheroidized or unevenly annealed state, which can produce localized hard spots. Coolant use helps control heat buildup and surface finish on finishing passes, and a sharp edge is preferable to a heavily honed one to avoid work-hardening the surface skin during light cuts.

Speeds below are for the annealed condition (~190-220 HB), which is how this steel is machined prior to water hardening.

Milling

Turning, parting, and grooving grade recommendations for W210 are not on file for this material yet. Browse the full turning/parting collection below for a grade suited to your hardness and finish requirements.