Steel
Metallurgy

High-carbon steel alloyed with chromium and tungsten for enhanced wear resistance and edge retention. Ideal for hard woods and heavy use. Forged by masters who prize its demanding nature, it rewards a skilled sharpener with extraordinary edges that outlast almost any other carbon steel.

Similar to Aogami #1 but with slightly lower carbon and tungsten content. Offers an excellent balance of edge retention and toughness, making it the most-used steel among Japanese master blacksmiths. The sweet spot of the Aogami family — demanding enough to be worthy, forgiving enough to be reliable.

The highest-carbon variant among Aogami steels. Includes vanadium and molybdenum for extreme edge retention and hardness. Revered and feared in equal measure — its edge outlasts almost everything, but requires a master's touch to sharpen properly. The pinnacle of the Hitachi carbon steel family.

Pure high-carbon steel with minimal impurities. Takes a laser-like edge and is easy to sharpen, but more brittle than Aogami. The traditional choice of master woodworkers who demand the finest possible cutting edge and sharpen their tools with religious dedication. Rust forms overnight if neglected.

The most widely used white steel. Slightly lower carbon than #1 for an excellent balance of extreme sharpness and workability. The most beloved steel among Japanese master craftsmen for its near-perfect balance: it sharpens with effortless ease and delivers razor edges that glide through the finest grain.

Lower-carbon variant of White Steel. Less pure, but significantly tougher and easier to sharpen. Often used for larger striking tools or entry-level blades where toughness is prioritized over maximum edge retention.

A high-carbon steel with slightly more impurities than Shirogami. Often used for saws and general-purpose tools. Easier to forge but does not reach the extreme sharpness or edge retention of Blue or White steels. A workhorse steel with an honest, reliable character.

Highly pure carbon steel imported from Sweden. Historically prized by Japanese blacksmiths for its exceptional purity and performance, rivaling the best domestic steels. Some legendary pre-war tool makers used it exclusively, and tools bearing this steel are treasured collector's items.

Extremely rare historical steel produced by Andrews Steel Company in the late 19th century. Known for achieving White #1 levels of keenness with Blue Super edge retention. Notoriously difficult to forge, requiring master-level heat control. Tools made from this steel are among the most coveted in the world.

Broad category of high-carbon steel widely used for general Japanese woodworking tools. Affordable, easy to sharpen, and highly functional, though it lacks the extreme refinement of the Hitachi paper steels. A democratic steel that puts functional tools in every craftsman's hands.

A remarkable Hitachi powder-metallurgy stainless steel with an extraordinary 3% carbon content — the highest of any commercial steel. Achieves hardness levels of 67–69 HRC, creating edges of uncanny keenness with stainless properties. Heat treatment demands extreme precision; it is unforgiving and expensive.

A powder-metallurgy high-speed steel from Hitachi, designed originally for industrial cutting tools. Japanese knife and tool makers adopted it for its exceptional hardness and wear resistance. The vanadium and cobalt additions produce carbides that resist abrasion beyond almost any other steel in this reference.

A powder-metallurgy stainless steel developed by Takefu Special Steel. R2 and SG2 refer to the same steel from different suppliers. Combines surprisingly good stainless properties with very high hardness and excellent edge retention. One of the most practical high-performance steels for everyday use.

Ginsan (Gingami #3) is a stainless steel from Hitachi with a carbon level approaching white steel — a deliberate design to bring near-Shirogami sharpness in a rust-resistant body. Loved by professional Japanese chefs who need stainless practicality without sacrificing the razor-keen edge that carbon steel provides.

The legendary steel produced by smelting iron sand (satetsu) in a traditional tatara furnace over three days. The bloom contains steel at varying carbon levels, which a swordsmiths then separates by eye. For tool use, the finest pieces are laminated into a hard hagane cutting edge. Represents the absolute summit of Japanese metallurgical tradition — both material and art object.

Steel smelted and folded by individual blacksmiths in their own forge. Unlike Tamahagane from a centralized tatara, Oroshigane is entirely the creation of one smith — iron ore or scrap iron is smelted, refined, and folded to drive out slag. The result varies entirely by the smith's skill and chosen materials. Some legendary Oroshigane exceeds anything that can be purchased commercially.

A high-grade stainless steel from Takefu Special Steel, featuring significant vanadium content for outstanding edge retention and hardness. Very popular with Japanese cutlery and knife makers targeting the premium segment who need consistent, high-performance stainless properties without resort to powder metallurgy.

A proprietary laminated construction used by some smiths: an Aogami Super core cladded between stainless steel jackets. The concept marries the legendary edge of Aogami Super with everyday rust resistance. The exposed cutting edge still requires diligent care, but the body of the tool never stains. Popular for premium plane blades marketed internationally.

San Mai ('three-layer') is the classic Japanese lamination: a hard carbon steel core (hagane) forge-welded between two layers of softer iron or steel (jigane). This produces a blade that takes a razor edge while the body provides toughness to resist chipping. Damascus refers to visible pattern-welded variants with dozens of alternating layers. Both traditions originate in functional necessity; the patterns visible in polished Damascus are a by-product of functional metallurgy, not decoration.

A standardized Japanese Industrial Standard (JIS) carbon tool steel. Slightly higher carbon than SK5 and lower than SK2, making it one of the most balanced general-purpose tool steels in the JIS classification. Widely used for saw blades, knives, and hand tools where consistent heat treatment and predictable performance matter more than ultimate edge retention.

Originally developed for machining applications, HSS (notably M2) has found its way into a niche of Japanese woodworking tools — particularly router bits, drill bits, and some specialty plane blades. Its extraordinary hot-hardness is irrelevant for woodworking, but its fine carbide structure and wear resistance make it compelling for specific applications where conventional carbon steel wears prematurely.