L3 is an AISI low-alloy special-purpose tool steel from the L-series, distinguished from its L1 and L2 relatives by a higher chromium content (typically 1.3-1.7%) and a small vanadium addition. That combination gives L3 noticeably better wear resistance than plain carbon or lightly alloyed L-series grades while keeping the alloy simple and reliably oil-hardening. The chromium level places L3 in the same general family as 100Cr6/52100 bearing steel chemistry — Wnr. 1.2067 is commonly cross-referenced with 100Cr6 in supplier catalogs — though L3's small vanadium content and its role as a tool/machine-part steel rather than a rolling-bearing steel set it apart in practice.

L3 is used for machine parts and tooling that need a step up in wear resistance over plain L1 without moving to a fully carbide-rich cold-work grade: gauges, forming rolls, small dies, arbors, and similar components where a hard, stable working surface matters more than deep hardenability in large sections.

The 100Cr6 cross-reference reflects a shared chemistry family (both are Cr-rich, oil-hardening, ~1% carbon steels under Wnr. 1.2067) rather than a strict standards identity — L3 and 100Cr6/52100 are closely related but not the same specification. The old page's hidden composition data (W 8.5-10%, Cr 3.0-3.75%, V 0.3-0.6%, no Ni) belonged to an unrelated tungsten hot-work steel and has been discarded.

L3 machines slightly harder than L1 due to its higher chromium content and small vanadium addition, but it remains well within the range of a moderately alloyed high-carbon tool steel. In the annealed condition (roughly 200-230 HB), the fine chromium and vanadium carbides present add some abrasive wear on the tool flank compared to plain L1, but nowhere near the carbide loading of a D-series cold-work steel. Chip formation is generally continuous and manageable with standard turning and milling geometries.

As with the rest of the L-series, most L3 parts are roughed and semi-finished before oil hardening, with grinding handling final precision after heat treatment. Coated carbide with moderate feeds and adequate rigidity gives consistent tool life; this is not a material that demands specialized tooling.

Starting-point ranges for annealed L3, set slightly below L1 to account for its added chromium and vanadium carbide content. Always verify with a test cut.

Turning

Parting / Grooving

Milling